Hispanic Foods - American Chemical Society

Chapter 3

Hispanic Dairy Products Michael H. Tunick

Downloaded by UNIV LAVAL on April 28, 2016 | http://pubs.acs.org Publication Date: December 4, 2006 | doi: 10.1021/bk-2007-0946.ch003

Eastern Regional Research Center, Dairy Processing and Products Research Unit, Agricultural Research Service, U.S. Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038

Hispanic-style cheeses and other dairy products are increasing in popularity in the U.S., prompting research into the chemical basis for their characteristics. Variations in Hispanic-style cheeses arise from differences in their processing parameters, which allow the properties of the cheese to range from hard and strongly flavored (Cotija), through semi-hard and meltable (Asadero, Oaxaca, and Mennonita), to soft and crumbly (Panela, Queso Blanco, Queso Fresco, and Requesón). Other dairy products that are prominent in Hispanic cuisine include creams (Crema Mexicana, Crema Agria, Natas), yogurts (cup, drinkable, and Jocoque), and desserts (Dulce de Leche, ice cream, Tres Leches). The diverse attributes of these products can be defined by the science underlying them.

Hispanics comprise 13.3% of the U.S. population, with two-thirds identifying themselves as Mexican (7). U.S. food companies are now targeting Hispanics (2) as well as non-Hispanics who are interested in trying Latin American food (5). Dairy products, unknown prior to Spanish colonization, are widely consumed in Mexico (4) and the rest of Latin America. The market in the U.S. for Hispanic cheeses (5), yogurts (6), and desserts (6) is growing, but the available literature on their chemistry and flavor is scant. A 1990 F A O report on dairy products in developing countries covered cheese, yogurt, and some

U.S. government work. Published 2007 American Chemical Society.

Tunick and González de Mejia; Hispanic Foods ACS Symposium Series; American Chemical Society: Washington, DC, 2006.

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34 desserts (7). More recently, Van Hekken and Farkye reviewed major Hispanic cheese varieties (8). A recent study revealed that over 85% of Mexicans and Mexican-Americans consumed cheese (4\ but most of the literature on Hispanic cheeses has dealt with bacterial contamination rather than the cheeses themselves. The consumption of other Hispanic-style dairy foods has also risen. Creams are an important part of Hispanic cuisine and their consumption has increased in the U.S. (9), but no papers covering these products have been published. Cup yogurt, drinkable yogurt, and Jocoque are products that are also popular among Hispanics. Dulce de Leche, Très Leches, and ice cream are examples of dairy-based Hispanic desserts, but research on these has also been limited. The purpose of this chapter is to describe representative Hispanic dairy products, emphasizing the information published about their chemistry.

Cheeses Hispanic cheeses can be classified into three categories, hard, semi-hard, and soft. The hard varieties are grating cheeses that tend to be strongly flavored, the semi-hard cheeses are less flavorful and usually made to be meltable, and the soft cheeses are often bland and crumbly. The flavor and the textural and functional properties of cheese rely on levels of moisture, casein, fat, salt, pH, and other factors. When the moisture content is low, the casein network is too dense to melt or stretch. N o melting or stretching takes place in cheese until the p H drops below 6.0. At p H 4.8-5.8, H * replaces C a P 0 , casein micelles fuse into a continuous network, and (especially at p H 5.0-5.4) cheese can melt and stretch. When the p H is lowered to 4.6, casein molecules aggregate again, the ability to stretch is lost, and meltability is reduced (10). The p H of milk in cheesemaking is sometimes reduced by the addition of food grade acid, but is traditionally lowered by the lactic acid resulting from bacterial metabolism of lactose. Many Hispanic cheeses are prepared with raw milk, which contains indigenous lactic acid bacteria. Raw milk cheese is not permitted in the U.S., so companies there use pasteurized milk, as do many of the larger cheese plants in Latin America. Since pasteurization inactivates microorganisms, starter cultures containing suitable bacterial strains must be added. Coagulation is performed with rennet, which traditionally contains chymosin enzyme derived from calf stomach but nowadays is likely to be derived from bacterial sources such as Rhizomucor miehei. The enzyme cleaves κ-casein, destabilizing the casein micelles and allowing them to bond to each other and form a curd. Hispanic cheese names are not standardized in the U.S. (77) or Latin America (72), leading to generic and trademarked brands that may not 4


35 correspond exactly to the varieties below. For instance, Queso Aflejo is used to describe both aged Cotija and aged Queso Blanco.

H a r d Cheeses The Hispanic cheeses in this category are represented by Cotija and its variations. The composition of Cotija is shown in Table I. Comparable to Parmesan, it is made with cow milk (or often goat milk in Latin America), thermophilic starter cultures, lipase enzymes for lipid breakdown, and C a C l to assist in coagulation. Thermophilic starter cultures are most active above room temperature, with Streptococcus thermophilus and Lactobacillus helveticus being common examples. Cotija is cooked at 65-70°C for 30 min and coagulated by rennet at 32-35°C in 40 min (13). The curd is milled and heavily salted, imparting a very salty flavor. The high manufacturing temperature and salt content lower the moisture level and makes Cotija a non-melting cheese with a strong casein matrix that results in a hard, brittle texture suitable for grating.


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Table I. Composition of Cotija (8,14,15)

Moisture (%) Fat(%) Salt (%) Protein (%) _H

Cotija 35-42 23-30 4.7-5.4 28-31 4.7-5.5

Semi-Hard Cheeses Oaxaca, Asadero, and Mennonita are examples of semi-hard Hispanic cheeses; their composition is shown in Table II. A l l are coagulated by rennet from whole milk after the addition of mesophilic starters (bacteria such as Lactococcus lactis, which are most active at room temperature), and all melt and slice well (8). Cooking of Oaxaca and Asadero curd takes place before draining all of the whey. Oaxaca is prepared and kneaded like Mozzarella, pulled into a strand, dry salted, and rolled into a ball (8, 16). Asadero, "fit for roasting," is pre-acidified by addition of dilute acid or acid whey. Traditionally, half of the milk is soured overnight and added to fresh milk (17) before rennet coagulation. This cheese is stretched, molded into a log or sphere, and sold fresh (8). The stretching step aligns the casein matrix, allowing the cheese to string when


36 heated. In the U.S., Asadero is usually a processed blend to enhance melting. Oaxaca has a sweet milk flavor (8) and Asadero is slightly tangy and buttery (72).


Table II. Composition of semi-hard, meltable cheeses (8,14,15)

Moisture (%) Fat(%) Salt(%) Protein (%) PH

Asadero 41-49 18-30 0.8-1.9 21-30 5.3-5.6

Oaxaca 40-46 23-25 1.4-1.8 24-27 5.0-5.5

Mennonita 41-45 21-30 1.4-2.3 22-26 5.0-5.3

Mennonita is manufactured in a manner similar to Cheddar, but contains more moisture. The curd is coagulated with rennet in 15-40 min, cut, and cooked at 37-45°C for up to 30 min. After whey drainage, the curd is cheddared - slabs of curd are stacked to promote additional whey removal (75). Mennonita has a shelf life of only 1-2 mo, and the product is generally eaten sooner. Both pasteurized and raw milk are used to make Mennonita in Mexico, and the resulting differences in the bacterial counts in the cheeses lead to differences in protein breakdown and rheological properties. Pasteurized milk Mennonita does not vary with season and undergoes less proteolysis than raw milk Mennonita, leading to differences in appearance and texture. Raw milk cheeses exhibit gas holes resulting from enzymatic activity, but these openings are virtually absent in pasteurized milk cheeses, which contain far fewer viable microorganisms. Raw milk cheese has seasonal effects, with winter cheese undergoing less casein proteolysis (79). Cheese made from raw milk in the summer is harder and springier than in other seasons because of its elevated protein content {19). A version of Mennonita is made in the U.S. from pasteurized milk, and is usually called Queso Quesadilla and Chihuahua™.

Soft Cheeses Panela, Queso Fresco, Queso Blanco, and Requeson are soft Hispanic cheeses that can be sliced and crumbled. They traditionally have relatively high pH values and are therefore not meltable. Table III lists the compositions of soft Hispanic cheeses. Panela is also called Queso de Canasta, "basket cheese" (20). It is coagulated by rennet set from pre-acidified whole cow milk (or, in Mexico, a combination of sheep and goat milk) with some acid added, and is cooked at 30-


37 Table III. Composition of soft, crumbly cheeses (8,14, IS) Panela


Moisture (%) Fat (%) Salt (%) Protein (%) PH

53-58 19-25 1.3-1.8 18-20 5.6-6.4

Queso Fresco 46-57 18-29 1-3 17-21 6.1

Queso Blanco 51-53 19-25 1.8-3.0 20-22 5.6

Requeson 74-75 7-8

Hispanic Foods - American Chemical Society

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