Mechanisms underlying the formation of complexes between maize

Subscriber access provided by University of Groningen

Article

Mechanisms underlying the formation of complexes between maize starch and lipids Chen Chao, Jinglin Yu, Shuo Wang, Les Copeland, and Shujun Wang J. Agric. Food Chem., Just Accepted Manuscript • DOI: 10.1021/acs.jafc.7b05025 • Publication Date (Web): 12 Dec 2017 Downloaded from http://pubs.acs.org on December 17, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Journal of Agricultural and Food Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 31

Journal of Agricultural and Food Chemistry

1

Mechanisms underlying the formation of complexes between maize

2

starch and lipids

3 Chen Chaoa, Jinglin Yua, Shuo Wangab*, Les Copelandc, Shujun Wanga*,

4 5 6

a

State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science &

7

Technology, Tianjin 300457, China

8 9

b

Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing

10

Technology & Business University, Beijing 100048, China

11 12

c

The University of Sydney, Sydney Institute of Agriculture, School of Life and

13

Environmental Sciences, NSW Australia 2006

14 15

* Corresponding authors: Dr. Shujun Wang or Dr. Shuo Wang

16

Mailing address: No 29, 13th Avenue, Tianjin Economic and Developmental Area (TEDA), Tianjin

17

300457, China

18

Phone: 86-22-60912486

19

E-mail address: [email protected] or [email protected]

20 21 22

1

ACS Paragon Plus Environment


23

Abstract: This study aimed to reveal the mechanism of formation of complexes

24

between native maize starch (NMS) and different types of lipids, namely palmitic acid

25

(PA), monopalmitate glycerol (MPG), dipalmitate glycerol (DPG) and tripalmitate

26

glycerol (TPG). The complexing index followed the order of MPG (96.3%) > PA

27

(41.8%) > TPG (8.3%) > DPG (1.1%), indicating that MPG formed more complexes

28

with NMS than PA, and that few complexes were formed between NMS and DPG and

29

TPG. The NMS-PA complex presented higher thermal transition temperatures and

30

lower enthalpy change than the NMS-MPG complex, indicating that although MPG

31

formed more starch complexes, they had less stable crystalline structures than the

32

complex between NMS and PA. X-ray diffraction (XRD) and Raman spectroscopy

33

showed that both MPG and PA formed V-type crystalline structures with NMS, and

34

confirmed that no complexes were formed between NMS and DPG and TPG. We

35

conclude that the monoglyceride formed more starch-lipid complex with maize starch

36

than PA, but that the monoglyceride complex had a less stable structure than that

37

formed with PA. The di- and tri-glycerides did not form complexes with maize starch.

38 39 40 41

Keywords: starch; fatty acids; glycerides; starch-lipid complexes.

42 43 44

2


Page 2 of 31

Page 3 of 31


45

Introduction

46

Starch, as a macro-constituent of many foods, has a major influence on the moisture

47

retention, viscosity, texture, consistency, shelf-life, and digestion of processed foods.1

48

The quality attributes of many processed cereal-based foods result from the specific

49

pasting, gelatinization and retrogradation properties of starch, which are influenced

50

strongly by additives.1,2 Lipids or emulsifiers are used in many foods to improve the

51

mouth-feel and quality of the final food products.3 When starch undergoes

52

gelatinization and retrogradation, the amylose chains can form inclusion complexes

53

with endogenous or exogenous lipids in foods. The formation of amylose-lipid

54

complexes reduces the solubility and swelling power of starch in water, alters the

55

rheological properties of pastes, increases gelatinization temperature, reduces gel

56

rigidity, retards retrogradation and reduces the susceptibility to enzymic

57

hydrolysis.2,4–9 Therefore, the formation of starch-lipid complexes and their impact on

58

the functionality of starch systems are of interest to food industry and for human

59

nutrition.10

60 61

Starch-lipid complexes have been studied extensively, with most of the lipids used

62

being fatty acids and monoglycerides.3,6,7,11–14 There have been no comprehensive

63

studies on the complexes of starch with fatty acids and their mono-, di- and

64

tri-glycerides. Studies with wheat starch showed that chain length and degree of

65

unsaturation of fatty acids and their monoglycerides had different effects on the

66

formation of starch-lipid complexes, and on pasting properties of starch.15,16

3



67

Lysolecithin, as a diacyl lipid, has been reported to form complexes with amylose.17

68

In contrast, triglycerides are generally thought to be unable to complex with

69

amylose.15–18 Edible oils have been used to study their effects of triglycerides on the

70

functional properties of starch.19–21

71 72

While many studies have investigated the effect of different lipids on properties of

73

starch and the formation of starch-lipid complex, there are many inconsistencies in the

74

literature, mainly due to different materials or experimental conditions used.22–26 This

75

report describes a comparative study, which is still lacking, on the effects of a fatty

76

acid and its corresponding mono-, di- and tri-glycerides on the formation mechanisms

77

and properties of starch-lipid complexes. This information is important for the

78

optimization of food processing, and to manipulate the quality attributes of finalized

79

food products. Hence in this study, the interactions of starch with palmitic acid and

80

the mono-, di- and tri-palmityl glycerols were examined. The structures of the

81

complexes formed in Rapid Visco Analyser (RVA) canisters were characterized by

82

X-ray diffraction, and LCM-Raman spectroscopy to enhance our understanding of the

83

mechanisms by which fatty acid and their glycerides form complexes with amylose.

84 85

Experimental section

86

Materials

87

Normal maize starch (NMS, 10.1% moisture and 22.4% amylose content), palmitic

88

acid (PA), monopalmitate glycerol (MPG), dipalmitate glycerol (DPG), tripalmitate

4


Page 4 of 31

Page 5 of 31


89

glycerol (TPG), with the lipid structures shown in Figure 1, were purchased from

90

Sigma Chemical Co. (St. Louis, MO, USA). All other chemical reagents were of

91

analytical grade.

92 93

Preparation of the starch-lipid mixtures

94

The starch-lipid mixtures were prepared to investigate the effects of lipid addition on

95

the structure and function of maize starch according to the methods of Wang et al

96

(2016)3 with minor modifications as follow. Firstly, 100 mg lipids were weighed

97

accurately and transferred into a glass beaker, to which about 50 mL ethanol (or for

98

TPG, hexane) was added with magnetic stirring. After complete dissolution of the

99

lipids, 2 g of starch was added to the solution to obtain a starch/lipid ratio of 20:1

100

(w/w). The mixture was stirred continuously in a fume hood until the ethanol or

101

hexane was evaporated completely. The resulting mixtures were stored at 4 oC for

102

further analysis.

103 104

Complexing index

105

The complexing index (CI) of starch-lipid complexes was measured according to the

106

method of Wang et al (2016)3 with minor modifications as follows. Starch-lipid

107

mixtures (0.4 g) prepared as described were weighed into 50 mL centrifuge tubes, and

108

distilled water added to a total weight of 5 g. After vortexing, the homogeneous

109

suspensions were heated in a boiling water bath with occasional shaking for 10 min or

110

until the starch was gelatinized completely. After cooling to room temperature, 25 mL

5



111

of distilled water was added to the gelatinized samples and the tubes vortexed for 2

112

min before centrifuging at 3000 × g for 15 min. An aliquot (500 µL) of the

113

supernatant was transferred into a test tube and mixed with 15 mL of distilled water

114

and 2 mL of iodine solution (2.0% KI and 1.3% I2 in distilled water). The UV

115

absorbance was measured at 620 nm. Maize starch was used as a reference. The CI

116

was calculated according to the formula:

117

CI(%)=100×(Absreference－Absstarch-lipid)/Absreference

118

Where Absreference is the absorbance of starch solution, Absstarch-lipid is the absorbance of

119

starch-lipid mixture.

120 121

Differential scanning calorimetry (DSC)

122

The thermal properties of the starch-lipid mixtures were measured using a differential

123

scanning calorimeter (200 F3, Netzsch, Germany) equipped with a thermal analysis

124

data station. Starch-lipid mixtures (3 mg) were weighed accurately into 40 µL

125

aluminum pans, and distilled water was added to give a water:mixture (or water:

126

starch) ratio of 3:1 (w/w). The pans were sealed, equilibrated overnight at room

127

temperature, heated from 20 to 120 oC at a rate of 10 oC /min, then cooled to 20 oC at

128

5 oC /min, and reheated to 120 oC at a rate of 10 oC /min. An empty pan was used as

129

the reference. The thermal transition parameters, onset temperature (To), peak

130

temperature (Tp), conclusion temperature (Tc), and enthalpy change (∆H), were

131

obtained through data recording software.

132

6


Page 6 of 31

Page 7 of 31


133

Pasting viscosity analysis

134

The viscosity properties of starch-lipid mixtures were determined using a Rapid Visco

135

Analyzer (RVA-4) (Perten Instrument Australia, Macquarie Park, NSW, Australia)

136

according to STD 1 procedure provided with the instrument with minor modification

137

as follows. Starch (2.5 g) and lipids (125 mg) were weighed sequentially into the RVA

138

canisters and the distilled water was added to make a total weight of 28 g. The

139

mixtures were stirred initially with the plastic paddle and then in the instrument at 960

140

rpm for the first 10 s, and continuously at 160 rpm until the completion of RVA

141

protocol. For the temperature profile, the sample was held at 50 oC for 1 min, and then

142

heated from 50 oC to 95 oC in 3 min and 42 s, held at 95 oC for 2 min and 30 s, cooled

143

to 50 oC in 3 min 48 s and held at 50 oC for 7 min. After measurements, the starch and

144

starch-lipid pastes were frozen immediately in liquid nitrogen, freeze-dried and

145

ground into power using a mortar and pestle. The powders were passed through a 150

146

µm sieve and stored at 4 oC for structural analysis.

147 148

X-ray diffraction (XRD)

149

The long-range molecular order of freeze-dried starch and starch-lipid samples

150

obtained from the RVA was examined using an X-ray diffractometer (D8 Advance,

151

Bruker, Germany) operating at 40 KV and 40 mA. The freeze-dried samples were

152

equilibrated over a saturated NaCl solution for one week before analysis. The XRD

153

patterns were obtained from 5° to 35° (2θ) at a scanning rate of 2 °/min and a step size

154

of 0.02°, as described by Wang et al (2016).27

7



Page 8 of 31

155 156

Laser confocal micro-Raman (LCM-Raman) spectroscopy

157

The LCM-Raman spectra of the freeze-dried starch and starch-lipid samples were

158

obtained using a Renishaw Invia Raman microscope

159

Gloucestershire, United Kingdom) equipped with a Leica microscope (Leica

160

Biosystems, Wetzlar, Germany); a 785 nm green diode laser source was used.27

161

Spectra in the range of 3200-100 cm-1 were acquired from at least six different

162

positions of each sample. The full width at half maximum (FWHM) of the band at

163

480 nm-1, which was used to characterize the short-range molecular order of starch

164

samples,28 was obtained by using the software of WiRE 2.0.

system (Renishaw,

165 166

Statistical analysis

167

All experiments were performed at least in triplicate and the results are reported as the

168

mean values and standard deviations. In the case of XRD, only one measurement was

169

conducted. Analysis of variance (ANOVA) by Duncan’s test (p < 0.05) was conducted

170

using the SPSS 10.0 Statistical Software Program (SPSS Inc. Chicago, IL, USA).

171 172

Results and discussion

173

CI of starch-lipid complexes

174

After complexation with PA, MPG, DPG and TPG, starch-lipid samples presented

175

different CI values (Table 1). Starch-MPG gave the highest CI value (96.3%),

176

followed by starch-PA (41.8%), starch-TPG (8.3%) and starch-DPG (1.1%). Similar

8


Page 9 of 31


177

results were also reported for wheat starch-fatty acid/monoglyceride systems in a

178

previous study.15 The much higher CI value, and hence greater complexation, of

179

NMS-MPG compared with NMS-PA is explained as being due to the higher solubility

180

and better emulsifying properties of MPG compared to PA. In comparison,

181

NMS-DPG and NMS-TPG had low CI values, indicating that DPG and TPG do not

182

readily form complexes with amylose, presumably due to their large steric hindrance

183

effects and their low water solubility.

184 185

Pasting properties

186

The RVA pasting profiles of maize starch and lipid complexes are shown in Figure 2.

187

The addition of MPG and, to a lesser extent, PA increased the final viscosity of NMS,

188

indicative of starch-lipid complex formation during the cooling stage, as has been

189

reported previously.3,15,28–30 The smaller increase of final viscosity for the NMS-PA

190

system indicated that less complexes were formed than with MPG. Similar results

191

were also observed in previous studies,15,28 which were explained on the basis of the

192

poor solubility of PA and its tendency to self-associate in preference to forming

193

starch-lipid complexes. The higher peak viscosity of the NMS-MPG system suggested

194

that a small amount of starch-lipid complexes formed during heating, making the

195

starch granule less susceptible to breakdown. DPG and TPG did not affect the pasting

196

viscosity profiles of NMS, consistent with the absence of NMS-lipid complexes with

197

these lipids, as observed previously.15,16

198

9



199

Thermal properties

200

The DSC thermograms, thermal transition temperatures (To, Tp, Tc) and enthalpy

201

change (∆H) of NMS and NMS-lipid mixtures are shown in Figure 3 and Table 2,

202

respectively. During the initial heating scan, NMS presented an obvious endothermic

203

gelatinization peak at 71 oC. A weak endothermic transition, representing the melting

204

of amylose-lipid complexes, was also observed at around 100 oC. For starch-lipid

205

mixtures, an additional endothermic peak, which partly overlapped with the peak for

206

starch gelatinization was observed. This additional peak was due to the melting of the

207

lipids.3,28

208 209

The amylose-lipid complex transitions of the NMS-lipid samples varied with the type

210

of lipids. The enthalpy change of NMS-MPG sample (3.7 J/g) was much higher than

211

those of NMS-PA (1.3 J/g), NMS-DPG (1.0 J/g), NMS-TPG (0.8 J/g) and NMS (0.7

212

J/g). The enthalpy change of amylose-lipid complexes has been proposed to reflect

213

the amount of complex and, to a lesser extent, the degree of ordered structure within

214

the complex.3,31 Compared with NMS, the higher enthalpy changes for NMS-MPG

215

and NMS-PA mixtures indicated that starch-lipid complexes were formed during DSC

216

heating, and that MPG formed more complexes than PA, consistent with the CI results.

217

The formation of starch-lipid complexes in heated starch-water mixtures has also been

218

reported.6,7,28,32,33 The absence of complex formation with the NMS-DPG and

219

NMS-TPG mixtures was a further indication that DPG and TPG do not form inclusion

220

complexes with amylose.

10


Page 10 of 31

Page 11 of 31


221 222

The NMS-MPG complex presented lower values for thermal transition temperatures

223

(82.2 oC, 95.9 oC, 104.1 oC for To, Tp and Tc, respectively) compared with the

224

NMS-PA complex (91.5 oC, 99.3 oC, 105.7 oC for To, Tp and Tc, respectively). These

225

data indicated that the NMS-MPG complex contained less stable ordered structures

226

than the NMS-PA complex, although MPG was more liable than PA to form

227

complexes with amylose.

228 229

During the cooling stage after the initial heating, all starch-lipid samples displayed

230

two exothermic transitions, which were attributed to the recrystallization of the lipid

231

(35-55 oC) and the formation of starch-lipid complex (65-80 oC).3,11,17,28,34 The

232

exothermic enthalpy change of NMS-MPG complex (2.5 J/g) was higher than that of

233

NMS-PA (2.1 J/g), NMS (1.5 J/g), NMS-DPG (0.7 J/g) and NMS-TPG (0.5 J/g),

234

further indicating that MPG formed more complexes with amylose than did the other

235

lipids during cooling. The lower exothermic enthalpy change of NMS-DPG and

236

NMS-TPG samples compared with NMS sample indicated that DPG and TPG may

237

hamper the formation of complexes between amylose and endogenous lipids.

238 239

Interestingly, the exothermic enthalpy changes of NMS and NMS-PA during cooling

240

were greater than the respective endothermic enthalpy changes during the initial

241

heating scan, consistent with our previous study.28 In contrast, the opposite results

242

were observed for the NMS-glyceride systems. We propose that PA, with a single long

11



243

aliphatic chain, can form more ordered structures or greater amount of complex

244

during the cooling stage than in the heating process. On the other hand, steric

245

hindrance by the glycerides may make the formation of starch-glyceride complexes

246

and their arrangement into ordered crystalline structures more difficult during cooling

247

stage.

248 249

On reheating of the cooled samples, an endothermic transition for NMS, NMS-PA,

250

NMS-MPG, NMS-DPG, and NMS-TPG samples was observed at about 100 oC, with

251

the enthalpy changes of 1.0, 1.8, 2.8, 0.5 and 0.5 J/g respectively. The greater enthalpy

252

change for the NMS-MPG sample confirmed that more complex had formed during

253

the cooling stage with this system than with the other NMS-lipid mixtures. The

254

thermal transition temperatures of the NMS-MPG complex were lower than those of

255

NMS-PA complex, further demonstrating that NMS-PA complex had a more ordered

256

structure than the NMS-MPG complex.

257 258

The NMS-PA complex had a greater exothermic enthalpy change during cooling than

259

the endothermic enthalpy change during reheating. Similar results were also reported

260

previously.17,28 This observation indicated that the less-ordered type I complex was

261

transformed into the more ordered type II complex, which might not melt completely

262

during reheating under the experimental conditions. In contrast, the exothermic

263

enthalpy change of NMS-MPG in the cooling stage was lower than the endothermic

264

enthalpy change during reheating, consistent with a previous study,6 suggesting steric

12


Page 12 of 31

Page 13 of 31


265

hindrance of MPG inhibited the transformation of type I into type II complex. DSC

266

heating has been proposed to promote the conversion of type I complex into more

267

ordered type II complexes,33 thus leading to higher energy input and enthalpy change

268

due to the melting of NMS-MPG complex on reheating.

269 270

X-ray diffraction

271

The X-ray diffraction patterns of native NMS and freeze-dried NMS and NMS-lipid

272

samples are shown in Figure 4. Native maize starch showed a typical A-type

273

diffraction pattern with peaks at 15.0, 17.0, 18.0 and 23.0° (2θ). After pasting in RVA,

274

the main diffraction peaks of starch crystallites disappeared, with only two weak

275

peaks at 12.8° and 19.8° (2θ) related to naturally present amylose-lipid complex. The

276

NMS-PA sample showed four clearly identified diffraction peaks at 2θ values of 7.5,

277

12.8, 19.8, 21.3 and 24.2°. The diffraction peaks at 12.8 and 19.8° (2θ) were due to

278

the formation of starch-lipid complex during RVA pasting, whereas the peaks at 7.5,

279

21.3 and 24.2° (2θ) are attributed to the uncomplexed fatty acid.15,28,35 Similar results

280

were also observed with NMS-MPG sample, except that diffraction peaks for free

281

MPG were not evident. These results indicated that MPG had better complexation

282

properties with NMS than PA, consistent with the results of CI and the enthalpy

283

change measurements. While MPG formed more complexes with NMS, the NMS-PA

284

complex had more ordered V-type crystalline structure, consistent with its higher

285

thermal transition temperatures (Table 2). No obvious V-type XRD pattern was

286

observed for the NMS-DPG and NMS-TPG samples, indicating that no complexation

13



287

occurred between NMS and DPG or TPG.

288 289

LCM-Raman spectroscopy

290

The LCM-Raman spectra (Figure 5) were obtained to characterize the short-range

291

molecular order of native NMS and freeze-dried starch and starch-lipid samples

292

obtained after RVA pasting. The values of full width at half maximum (FWHM) of the

293

band at 480 cm-1, which are listed in Table 1, can be used to characterize the degree of

294

ordered starch structure. Previous studies have shown that the FWHM values decrease

295

with increasing short-range molecular order of starch structure.28,36,37 Native NMS

296

had the smallest FWHM value of 16.5, whereas the NMS paste had the largest

297

FWHM value of 21.4. NMS-DPG and NMS-TPG samples showed the similar FWHM

298

values (21.5 vs. 21.2) to NMS paste, indicating no ordered complexes formed

299

between starch and DPG and TPG, consistent with the other results of this study. The

300

NMS-PA and NMS-MPG samples gave FWHM values of 18.3 and 16.9, respectively,

301

indicating the presence of ordered structures in these mixtures. As expected, the

302

NMS-MPG sample presented the lower FWHM value, suggesting it contained more

303

ordered structures than NMS-PA, consistent with the results of CI and enthalpy

304

change.

305 306

Mechanisms for the formation of starch-lipid complexes

307

Many studies have shown that starch can form inclusion complexes with lipids,

308

especially free fatty acids and monoglycerides. However, relatively few studies have

14


Page 14 of 31

Page 15 of 31


309

compared the nature of the complexes formed. While amylose is the major component

310

of starch to complex with lipids, amylopectin is also known to interact with lipids in

311

some way.3 In this study, palmitic acid and its mono-, di- and tri-glycerides were used

312

to reveal the mechanisms underlying the formation of starch-lipid complexes, as

313

proposed in Figure 6.

314 315

Heating and cooling of the starch-PA mixture, resulted in the formation of V-type

316

ordered complexes. The long aliphatic hydrophobic chain of PA can be inserted into

317

the helical cavity of amylose, resulting in the ordered arrangement of complexes

318

(Figure 6A). However, the poor solubility of PA in aqueous systems limits the amount

319

of complexes formed. In contrast, the interaction between starch and MPG was

320

enhanced due to the increased solubility of MPG and its emulsifying action, which

321

can lead to the formation of a greater amount of starch-MPG complexes. However,

322

the arrangement of amylose-MPG complexes into a highly ordered V-type crystalline

323

structure was impeded by the steric hindrance of the glyceride (Figure 6B). As a result,

324

the starch-PA complex presented as more ordered, with higher thermal transition

325

temperatures and lower enthalpy change compared with starch-MPG complex. No

326

complexes were detected by CI, DSC, XRD, Raman and RVA analyses in mixtures of

327

starch with DPG and TPG, presumably because of their bulky molecular size causing

328

steric hindrance and low water solubility resulting in two separate phase in this

329

system (Figure 6C).

330

15



331

In summary, the interaction mechanisms of maize starch and palmitic acid, and the

332

corresponding mono-, di- and tri-glycerides, were revealed using a range of

333

techniques that showed the structure and the solubility of the lipid components have

334

significant effects on the formation and structural order of starch-lipid complexes. The

335

monoglyceride formed a greater amount of starch-lipid complex than palmitic acid,

336

but the complex between normal maize starch and palmitic acid had more ordered

337

structures than the corresponding monopalmityl glyceride complex. The higher

338

solubility and emulsifying action of monopalmityl glyceride are proposed to promote

339

greater complex formation. No complexes were detected between maize starch and

340

the di- and tri-glycerides.

341 342

Acknowledgements

343

The authors gratefully acknowledge the financial support from the National Natural

344

Science Foundation of China (31430068, 31522043).

345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 16


Page 16 of 31

Page 17 of 31


360

References

361

(1) Wang, S.; Copeland, L. Molecular disassembly of starch granules during

362

gelatinization and its effect on starch digestibility: a review. Food Funct. 2013, 4 (11),

363

1564–1580.

364

(2) Copeland, L.; Blazek, J.; Salman, H.; Tang, M. C. Form and functionality of

365

starch. Food Hydrocoll. 2009, 23(6), 1527–1534.

366

(3) Wang, S.; Wang, J.; Yu, J.; Wang, S. Effect of fatty acids on functional properties

367

of normal wheat and waxy wheat starches: A structural basis. Food Chem. 2016, 190,

368

285–292.

369

(4) Crowe, T. C.; Seligman, S. A.; Copeland, L. Inhibition of enzymic digestion of

370

amylose by free fatty acids in vitro contributes to resistant starch formation. J. Nutr.

371

2000, 130 (8), 2006–2008.

372

(5) Ozcan, S.; Jackson, D. S. The impact of thermal events on amylose-fatty acid

373

complexes. Starch - Stärke 2002, 54 (12), 593–602.

374

(6) Tufvesson, F.; Wahlgren, M.; Acids, P. F. Formation of amylose-lipid complexes

375

and effects of temperature treatment. Part 1. Monoglycerides. Starch - Stärke 2003,

376

55(2), 61–67.

377

(7) Tufvesson, F.; Wahlgren, M.; Acids, P. F. Formation of amylose-lipid complexes

378

and effects of temperature treatment. Part 2. Fatty acids. Starch - Stärke 2003, 55(3-4),

379

138–149.

380

(8) Garcia, M. C.; Franco, C. L. M. L. Effect of glycerol monostearate on the

381

gelatinization behavior of maize starches with different amylose contents. Starch

17



Page 18 of 31

382

Stärke 2015, 67 (1–2), 107–116.

383

(9) Kawai, K.; Takato, S.; Ueda, M.; Ohnishi, N.; Viriyarattanasak, C.; Kajiwara, K.

384

Effects of fatty acid and emulsifier on the complex formation and in vitro digestibility

385

of gelatinized potato starch. Int. J. Food Prop. 2017, 20 (7), 1500–1510.

386

(10) Panyoo, A. E.; Emmambux, M. N. Amylose-lipid complex production and

387

potential health benefits: A mini-review. Starch

388

(11)

389

amylose-monoglyceride complex in a starch matrix. Carbohydr. Polym. 2000, 43 (4),

390

359–365.

391

(12) Putseys, J. A.; Lamberts, L.; Delcour, J. A. Amylose-inclusion complexes:

392

Formation, identity and physico-chemical properties. J. Cereal Sci. 2010, 51 (3),

393

238–247.

394

(13) Kawai, K.; Takato, S.; Sasaki, T.; Kajiwara, K. Complex formation, thermal

395

properties, and in-vitro digestibility of gelatinized potato starch-fatty acid mixtures.

396

Food Hydrocoll. 2012, 27 (1), 228–234.

397

(14) Marinopoulou, A.; Papastergiadis, E.; Raphaelides, S. N.; Kontominas, M. G.

398

Structural characterization and thermal properties of amylose-fatty acid complexes

399

prepared at different temperatures. Food Hydrocoll. 2016, 58, 224–234.

400

(15) Tang, M. C.; Copeland, L. Analysis of complexes between lipids and wheat

401

starch. Carbohydr. Polym. 2007, 67 (1), 80–85.

402

(16) Liang, X.; King, J. M.; Shih, F. F. Pasting property differences of commercial

403

and isolated rice starch with added lipids and β-cyclodextrin. Cereal Chem. 2002, 79

Tufvesson,

F.;

Eliasson,

A.

C.

Stärke. 2017, 69 (7). Formation

18


and

crystallization

of

Page 19 of 31


404

(6), 812–818.

405

(17) Eliasson, A. C. Interactions between starch and lipids studied by DSC.

406

Thermochim. Acta 1994, 246 (2), 343–356.

407

(18) Eliasson, A. C.; Finstad, H.; Ljunger, G. A Study of starch-lipid interactions for

408

some native and modified maize starches. Starch

409

(19) Davis, E. A.; Grider, J.; Gordon, J. Microstructural evaluation of model starch

410

systems containing different types of oils. Cereal Chem, 1986, 63 (5), 427–430.

411

(20) Navarro, A. S.; Martino, M. N.; Zaritzky, N. E. Modelling of rheological

412

behaviour in starch-lipid systems. Food Sci. Technol. Technol. 1996, 29 (7), 632–639.

413

(21) Chen, X.; He, X.; Fu, X.; Zhang, B.; Huang, Q. Complexation of rice starch/flour

414

and maize oil through heat moisture treatment: Structural, in vitro digestion and

415

physicochemical properties. Int. J. Biol. Macromol. 2017, 98, 557–564.

416

(22) De Pilli, T.; Derossi, A.; Talja, R. A.; Jouppila, K.; Severini, C. Starch-lipid

417

complex formation during extrusion-cooking of model system (rice starch and oleic

418

acid) and real food (rice starch and pistachio nut flour). Eur. Food Res. Technol. 2012,

419

234 (3), 517–525.

420

(23) De Pilli, T.; Derossi, A.; Talja, R. A.; Jouppila, K.; Severini, C. Study of

421

starch-lipid

422

extrusion-cooking technology. Innov. Food Sci. Emerg. Technol. 2011, 12 (4),

423

610–616.

424

(24) Siswoyo, T. A.; Morita, N. Physicochemical studies of defatted wheat starch

425

complexes with mono and diacyl-sn-glycerophosphatidylcholine of varying fatty acid

complexes

in

model

system

Stärke 1988, 40 (3), 95–100.

and

real

19


food

produced

using


426

chain lengths. Food Res. Int. 2003, 36 (7), 729–737.

427

(25) Hoover, R.; Hadziyev, D. Characterization of potato starch and its

428

monoglyceride complexes. Starch

429

(26) Ai, Y.; Hasjim, J.; Jane, J. L. Effects of lipids on enzymatic hydrolysis and

430

physical properties of starch. Carbohydr. Polym. 2013, 92 (1), 120–127.

431

(27) Wang, S.; Wang, J.; Zhang, W.; Li, C.; Yu, J.; Wang, S. Molecular order and

432

functional properties of starches from three waxy wheat varieties grown in China.

433

Food Chem. 2015, 181, 43–50.

434

(28) Wang, S.; Zheng, M.; Yu, J.; Wang, S.; Copeland, L. Insights into the formation

435

and structures of starch-protein-lipid complexes. J. Agric. Food Chem. 2017, 65 (9),

436

1960–1966.

437

(29) Eliasson, B. A. X.; Carlson, T. L. Some effects of starch lipids on the thermal

438

and rheological properties of wheat starch. Starch

439

(30) Zhang, G.; Hamaker, B. R. A three component interaction among starch, protein,

440

and free fatty acids revealed by pasting profiles. J. Agric. Food Chem. 2003, 51 (9),

441

2797–2800.

442

(31) Eliasson, A.-C.; Krog, N. Physical properties of amylose-monoglyceride

443

complexes. J. Cereal Sci. 1985, 3 (3), 239–248.

444

(32) Derycke, V.; Vandeputte, G. E.; Vermeylen, R.; De Man, W.; Goderis, B.; Koch,

445

M. H. J.; Delcour, J. A. Starch gelatinization and amylose-lipid interactions during

446

rice parboiling investigated by temperature resolved wide angle X-ray scattering and

447

differential scanning calorimetry. J. Cereal Sci. 2005, 42 (3), 334–343.

Stärke 1981, 33 (9), 290–300.

Stärke 1981, 33(4), 130–134.

20


Page 20 of 31

Page 21 of 31


448

(33) Le Bail, P.; Bizot, H.; Ollivon, M.; Keller, G.; Bourgaux, C.; Buléon, A.

449

Monitoring the crystallization of amylose-lipid complexes during maize starch

450

melting by synchrotron X-ray diffraction. Biopolymers 1999, 50 (1), 99–110.

451

(34) C.G. Biliaderis, C.M. Page, L. S. and R. R. S. Thermal behavior of amylose-

452

lipid complexes. Carbohydr. Polym. 1985, 5 (5), 367–389.

453

(35) Zhang, B.; Huang, Q.; Luo, F. xing; Fu, X. Structural characterizations and

454

digestibility of debranched high-amylose maize starch complexed with lauric acid.

455

Food Hydrocoll. 2012, 28 (1), 174–181.

456

(36) Wang, S.; Sun, Y.; Wang, J.; Wang, S.; Copeland, L. Molecular disassembly of

457

rice and lotus starches during thermal processing and its effect on starch digestibility.

458

Food Funct. 2016, 7 (2), 1188–1195.

459

(37) Wang, S.; Zhang, X.; Wang, S.; Copeland, L. Changes of multi-scale structure

460

during mimicked DSC heating reveal the nature of starch gelatinization. Sci. Rep.

461

2016, 6 (1), 28271.

462 463 464 465 466 467 468 469 470

21



471

Figure captions

472 473

Figure 1. Structural formulas of PA, MPG, DPG and TPG

474 475

Figure 2. RVA profiles of NMS and NMS-lipid mixtures.

476 477

Figure 3. DSC curves of NMS and starch-lipid mixtures. (A) initial heating and

478

reheating process; (B) cooling process. NMS (a), NMS-PA (b), NMS-MPG (c),

479

NMS-DPG (d), NMS-TPG (e). Rescan of NMS, NMS-PA, NMS-MPG, NMS-DPG

480

and NMS-TPG (a1, b1, c1, d1 and e1).

481 482

Figure 4. XRD patterns of NMS and NMS-lipid samples. Native NMS (a), NMS-PA

483

(b), NMS-MPG (c), NMS-DPG (d), NMS-TPG (e), NMS paste (f).

484 485

Figure 5. LCM-Raman spectroscopy of NMS and NMS-lipid samples. Native NMS

486

(a), NMS-PA (b), NMS-MPG (c), NMS-DPG (d), NMS-TPG (e), NMS paste (f).

487 488

Figure 6. Mechanisms for the formation of starch-lipid complexes.

489 490 491 492 493 494

22


Page 22 of 31

Page 23 of 31


495

Figure 1

496 497 498 499 500

PA

MPG

501 502 503 504 505 506 507

DPG

TPG

508 509 510 511 512 513 514 515 516 517 518 519 520 521

23



Figure 2

100

4500 NMS-TPG NMS-DPG NMS-MPG NMS-PA NMS

4000 3500

80

2500

o

Viscosity (cP)

3000

90

Temperature ( C)

522

Page 24 of 31

70

2000 1500

60

1000 500

50

0 -500 -1 0

1

2

3

4

5

6

7

8

40 9 10 11 12 13 14 15 16 17 18 19

Time (min) 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 24


Page 25 of 31


546

Figure 3

547

8.0

A

7.5 7.0

e1 e

6.5 6.0

d1 d

DSC flow

5.5 5.0

c1 c

4.5 4.0

b1 b a1 a

3.5 3.0 2.5 2.0 30

40

50

60

70

80

90

100

110

o

Temperature ( C)

-0.8

B

-0.9 -1.0

e

-1.1 -1.2

DSC flow

-1.3

d

-1.4 -1.5

c

-1.6

b

-1.7 -1.8

a

-1.9 -2.0 30

40

50

60

70

80 o

Temperature ( C) 548 549 550 551 552

25


90

100

110


553 554

Page 26 of 31

Figure 4

Diffraction intensity (cps)

100000

a 75000

b c

50000

d e f

25000

5

10

15

20

25

Diffraction (2θ) 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569

26


30

35

Page 27 of 31


570

Figure 5

90000

Relative Intensity

75000

a

60000

b 45000

c

30000

d 15000

e 0

f -15000 3500

3000

2500

2000

1500

1000 -1

Wavenumbers (cm ) 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 27


500

0


594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637

Figure 6

A

B

C

28


Page 28 of 31

Page 29 of 31


638

Table 1. Complexing index and FWHM at 480 cm-1 of starch-lipid mixtures Samples Complexing index (%) FWHM at 480cm-1 Native starch ND 16.5±0.1a NMS-PA 41.8±1.8c 18.3±0.4c NMS-MPG 96.3±0.5d 16.9±0.3b NMS-DPG 1.1±0.8a 21.5±0.2d NMS-TPG 8.3±0.7b 21.2±0.3d NMS paste ND 21.4±0.4d

639

Values are means ± SD. Means with the same letters in a column do not differ significantly (p >

640

0.05).

641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673

ND, not detected.

29



674

Table 2. Thermal transition parameters of starch-lipid complexes Samples

To (℃)

Tp (℃)

Tc (℃)

∆H (J/g)

NMS NMS-PA NMS-MPG NMS-DPG NMS-TPG

heating

89.2±0.4g 91.5±0.6h 82.2±0.4bc 88.8±0.6g 89.0±1.2g

97.4±0.2d 99.3±0.4e 95.9±0.4c 96.9±0.3cd 97.9±0.7d

104.1±0.7de 105.7±0.7f 104.1±1.3de 103.3±0.1d 105.5±0.9ef

0.7±0.0ab 1.3±0.1d 3.7±0.1j 1.0±0.3c 0.8±0.2bc

cooling

80.1±0.1a 80.5±0.4ab 82.5±1.0c 80.5±0.5ab 81.9±1.2abc

77.7±0.4a 77.5±0.8a 79.8±0.3b 77.8±0.4a 79.1±0.9b

68.8±0.1a 70.7±0.7b 74.0±1.0c 69.9±0.8ab 69.1±0.8a

1.5±0.0e 2.1±0.1g 2.5±0.1h 0.7±0.1ab 0.5±0.1a

NMS

85.2±0.8de

97.0±0.9cd

103.1±0.1d

1.0±0.1c

NMS-PA

86.3±1.0def

99.9±0.8e

106.8±0.7f

1.8±0.1f

NMS-MPG reheating

84.7±1.7d

96.9±0.2cd

103.6±0.3d

2.8±0.1i

NMS-DPG

87.8±0.8fg

97.3±0.2d

102.9±0.3d

0.5±0.0a

NMS-TPG

86.8±0.9ef

97.6±0.2d

103.3±0.9d

0.5±0.1a

NMS NMS-PA NMS-MPG NMS-DPG NMS-TPG

675 676 677 678

Page 30 of 31

Values are the means ± SD. Means with similar letters in a column do not differ significantly (p > 0.05).

679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 30


Table of Contents Graphic 4.4

e-rescan of NM S-TPG d-rescan of NM S-DPG c-rescan of NM S-M PG b-rescan of NM S-PA a-rescan of NM S

4.0

DSC thermogram e d

3.6

DSC flow

697 698 699 700 701 702 703


Tp

c 3.2

b a

2.8

30

40

50

60

70

80

90

100

110

o

Temperature ( C)

100000

Diffraction intensity (cps)

Page 31 of 31

a-Native NM S b-NM S-PA c-NM S-M PG d-NM S-DPG e-NM S-TPG f-NM S paste

X-ray diffraction a

75000

b c

50000

d e f

25000

5

10

15

20

25

Diffraction (2 θ )

31


30

35

Mechanisms underlying the formation of complexes between maize

Recommend Documents