Textured and shaped oilseed protein food products

The major emphasis in developing textured and shaped protein foods has been with the use of soy proteins. The availability at a low stable price, the high protein content and quality, and the inherent chemical properties of the protein allowing for unique structure development are major reasons for its strong world-wide use. The changing economic trends of many basic protein foods are creating a need for the use of unique textured proteins either as ingredients in existing foods or allowing improved functionality in new products. The two main procedures for texturing and shaping oilseed protein are spinning of protein isolates, and direct extrusion of flour. The spinning technique is more expensive and has greater product functionality in contrast to the direct extrusion method. Consumer acceptance is in large part correlated with the technological success of imparting desirable colors, flavors and textural properties in the finished food product. Examples of these variations are given. The use level of these textured proteins, particularly in meat products, are restricted by labeling standards. The present regulations are not clearly defined. Current proposals for labeling textured vegetable proteins when used with meat products involve standards on a ratio to meat basis. One of 21 papers presented at the Symposium, “Oilseed Processors Challenged by World Protein Need,” ISF-AOCS World Congress, Chicago, September 1970.     

Marketing considerations for improved protein food products

The conventional approach to marketing of improved products in the retail commercial markets of highly industrialized Western countries is of little utility in meeting presently unfulfilled protein needs of the underdeveloped countries. To be effective and accepted by the target consumers, improved protein foods must be classless, and must be introduced simultaneously at all levels of the economy. This can rarely be accomplished by the conventional business approach. New enterprise structures must be developed in which private companies can participate in joint ventures with governments, cooperatives and voluntary agencies. Successful market development in the less developed countries demands a systems approach in which interrelationships among food availabilities, nutritional needs, acceptability factors and purchasing power are evaluated in the context of the total food system of the country. One of 21 papers presented at the Symposium, “Oilseed Processors Challenged by World Protein Need,” ISF-AOCS World Congress, Chicago, September 1970.     

Cottonseed oil

Research on the effects of genetics and growing location on cottonseed has shown that oil and fatty acid composition could be improved if geneticists and agronomists would strive for improved seed quality as vigorously as they do for improved fiber quality. Breeding of glandless or gossypol-free cottonseed was a genetic breakthrough. Glandless varieties are now available that produce yields having the quality of fiber and seed equivalent to those of glanded cultivars. Oil, food-grade lecithin and meal byproducts are readily processed from glandless cottonseeds because of the absence of gossypol. Major research programs on cottonseed processing include: (a) testing alternative screw-press and extrusion operations for efficient direct solvent oil extraction; (b) developing alternative solvent extraction systems with ethanol, isopropanol and supercritical fluids; (c) using gas chromatographic/mass spectrophotometric techniques to characterize enzymatic and nonenzymatic mechanisms that produce secondary oxidation off-flavor products; and (d) controlling hexane losses in solvent extraction systems.     

Cottonseed preparation

Conventional methods of cottonseed preparation are reviewed and described, including seed cleaning, saw delinting, dehulling, conditioning, and flaking. The use of screw presses for prepress conditioning ahead of solvent extraction is discussed as compared to conditioning for direct solvent extraction. Newer methods and proposed alternate methods of cottonseed preparation are discussed including: abrasive delinting, acid delinting by gas and liquid acid, and the decorticating of undelinted seed. The effect of cracking rolls, moisture addition, moist cooking and flaking on gossypol gland rupture, the binding of gossypol to protein, and the effect of these processing or preparation variables on the residual oil in the extracted meal and on the oil quality are discussed.     

Wheat gluten applications in food products

Vital wheat gluten has traditionally been noted for its functional benefits in various bakery applications. In recent years extensive research and development work has taken place to more clearly identify wheat gluten’s unique characteristics and functional properties. As a result, many new and novel applications have been developed. The on-going potential of this exciting protein ingredient, in its native or modified forms, will only be limited by the imagination of those formulating new products.     

Texturized protein products

Texture is changed in oilseed protein fractions by mechanical and chemical means in specialized equipment. Processing conditions are closely controlled to ensure end product forms wanted. The arrangement of equipment used in the production of textured proteins is discussed as it relates to a commercial plant design. The nature of feed materials and details of processing conditions required to produce texture in soy protein are presented. Other forms of textured oilseed protein are discussed.     

Rapeseed protein products

During recent years somewhat different methods of producing rapeseed protein concentrates (RPC) and isolates (RPI) have been developed. Texturizing of RPC has also been studied. Functional properties of RPC such as solubility, water-and fat-binding, emulsifying and foaming have been studied together with their organoleptic properties. Very bland RPC can be produced. How variables obtained in the instrumental analysis are related to those obtained in the sensory analysis has also been studied. Rapeseed flours are comparable to soy flours in water absorption and give higher fat absorption. Oil emulsification and whippability values depend on processing. Rapeseed protein concentrates, and isolates show excellent water- and fat-holding capacity. The isolate is high in oil emulsification and whipping characteristics. Rapeseed protein products can therefore be used as extenders or binders in meat patties or sausages. Their use in bread and other food items also has been studied. Due to high contents of lysine, methionine and cysteine, rapeseed proteins have a higher nutritive value than any other known vegetable protein. Their nutritive value is as high as that of good animal proteins. This has been shown in growth studies on rats and in a nitrogen balance study on studient volunteers. The safety of RPC has been tested through many years. With the exception of a negative effect on the zinc balance in rats, which can be compensated, no negative finding has been recorded.     

Stability of coconut oil in food products

The active oxygen method (AOM) stability of refined coconut oil is generally 250 hr; however, samples with as low a stability as 30 hr have been obtained. The addition of BHA, BHT and citrate increased the AOM stability to about 350 hr even though the initial stability was 30 or 250 hr. Refined coconut oil samples which hydrolyzed from 2 to 10 times as rapidly as normal oils have been encountered. Such samples are undesirable for food production as soapy off-flavors may be produced. The rate of hydrolysis of coconut oil samples was evaluated by a simple laboratory test. Coconut oil free fatty acids produced a soapy off-flavor at a lower level in sweet foods than in salty ones. Soapy off-flavors were produced in a low moisture food containing coconut oil by the lipase activity of cinnamon.     

Fatty acid profile in baby food products

The fatty acid composition in the lipid phase of 64 commercially available baby food products, of two different batches each, was analyzed. They comprised vegetable products for babies of five, eight, and twelve months and fruit and cereal products of three different brands. The comparison of the composition of the saturated (C18:0, C16:0, C14:0, C12:0, C10:0), the unsaturated monoenoic (C18:1n9 and C16:1n7) and the polyenoic (C18:2n6 and C18:3n3) fatty acids was determined by gas chromatography. All analyzed baby food products provided well‐balanced amounts of saturated fatty acids on the one hand (saturated fatty acids (SFA) 31—37% of total fatty acids) and unsaturated fatty acids on the other hand (monounsaturated fatty acids (MUFA) 23—26% and polyunsaturated fatty acids (PUFA) 38—46% of total fatty acids, respectively). The P/S‐ratio in vegetable products of five months reached a value of 1.5, in all other analyzed products it was around 1. The n‐6:n‐3‐ratio was 10:1 in fruit and cereal products, followed by 11.6:1 in vegetable products of eight and twelve months and 13.5:1 in the group of vegetable products of five months. Since there is a lack of arachidonic acid and docosahexaenoic acid in baby food products, it might be of advantage to consider whether such products should be supplemented by these long‐chain polyunsaturated fatty acids.     

茚三酮比色法与甲醛滴定法测定棉籽粕蛋白水解度的比较

本文选用中性蛋白酶水解棉籽粕蛋白,对不同酶解时间的棉籽粕蛋白水解液的水解度分别用茚三酮比色法及甲醛滴定法进行测定。结果表明,与甲醛滴定法相比,茚三酮比色法更简便、更快速,且灵敏度高、可重复性强。是最适合测定低浓度棉籽蛋白水解液水解度的方法。     

A review of antioxidant analysis in food products

To permit proper usage of antioxidants by the food processor and permit control under applicable governmental regulations, it is necessary to have adequate analytical methods. Such methods should both positively identify and provide a quantitative assay for the additive. Due to the complex nature of foods, analysis of an antioxidant in the very small quantities used presents a very real problem. Solvent extraction and/or steam distillation techniques are employed to separate the antioxidants from the food. Ultraviolet spectra, gas chromatography and colorimetric techniques are used to identify and determine the quantity of each antioxidant present. Slight variations are necessary for each type of food.