Industrial corn flour enrichment with whole amaranth flour and milling fractions in corn-based products

Whole flour and milling fractions of raw amaranth seeds were used in 90:10, 80:20 and 50:50 mixtures with industrialized corn flour (MINSA) to prepare tortillas and arepas, basic nutritional foods in several Latin American countries. The three corn-amaranth mixtures showed a good protein and fat content as well as amino acid profile, and presented adequate physical characteristics for making tortillas. Amaranth whole flour and commercial corn flour mixtures in the proportion of 80:20 and 50:50 were found suitable for the preparation of arepas. Protein and fat content were substantially improved, with no changes in organoleptic characteristics. The Mexican type of Amaranthus cruentus, selected due to its availability and bromatologic properties, yielded products of excellent nutritional quality, according to their amino acid content and protein efficiency ratio (PER). The protein-rich (1R) and starchy (2-R) fractions obtained by air classification, also yielded good results when substituting amaranth flour. The afore-mentioned flours and air-classified fractions of the 50:50 mixtures proved to be adequate in gruel preparations when used in 1:8 and 1:12 dilutions, as they improved their organoleptic characteristics. Flakes and extrudates were also used, yielding products with a 13.3-15% protein content, 1.7-3.7% fat, and 65.2-74.2% carbohydrates. In addition, extrudates were utilized to prepare snacks of better nutritional quality than existing similar commercial products. Improvement of the tortilla's mineral and fatty acid contents was achieved in every case. Enrichment of this product with whole amaranth flour is, therefore, recommendable for use in programs aimed at improving the nutritional status of the population.     

Enrichment of precooked white corn flour (Zea mays) with amaranth seed flour (Amaranthus sp.)

Three mixtures of precooked white corn flour with 10, 20 and 30% amaranth flour were prepared. The sedimentation and consistency of the mixtures differed from those of the white corn flour, but without altering the capacity of dough formation to prepare arepas. The protein, fiber, and ash contents were higher than those of the precooked white corn flour. The functional properties of water and oil absorption increased in 20 and 10%, respectively. During the three-month storage, the protein and fat contents were not altered. Acceptability tests of the arepas were carried out and results indicated that those mixtures prepared with 10% and 20% substitution levels were acceptable from the sensory point of view. The protein quality was analyzed in terms of protein efficiency ratio (PER), which proved to be higher than that of the commercial white corn flour (PER 1.93), and the apparent digestibility was 92%. As far as lysine is concerned, results showed that arepas prepared with the mixture containing 10% amaranth (1.6 g lysine/100 g protein) and 20% (2.0 g lysine/100 g protein) also proved to be higher than the commercial white corn flour arepas (0.7 g lysine/100 g protein). Based on the above findings, enrichment of commercial white corn flour with grain amaranth flour, prior to the preparation of arepas, a product of high consumption in Venezuela as part of the habitual diet, is recommended.     

Development on a rice-based food product, for children

An infant dehydrated rice-based food product, complemented with soybean flour, was developed. To improve its nutritional and organoleptic characteristics, fruits were also added. Ingredients were first precooked and dried in a drum-dryer, obtaining a final product, as flakes, with a 2 to 3% water content. This rehydrates easily with liquids such as milk, water or "panela" (refined and concentrated sugar cane syrup). The sensory panel did not detect any difference between formulations containing 10, 15 and 20% soybean, respectively.     

Sesame seed (Sesamum indicum, L.). II. Use of sesame flour in protein mixtures

The results obtained in the first part of this study demonstrated that the sesame flour protein is of reasonable quality and can be utilized, although it has a low lysine content and is rich in sulfur amino acids. Based on the initial data, the sesame flour was supplemented with other meals: "carioca" beans, pigeon pea, and soybean. Nine diets were prepared and the best combination was that of 50% sesame flour protein and 50% pigeon pea, the PER of which was 2.28. Breads were made with these systems, as follows: 100% sesame flour, 100% wheat flour, 50% sesame flour + 50% wheat flour; 30% sesame flour + 70% wheat flour; 30% sesame flour + 30% soybean flour + 40% wheat flour. These were evaluated through sensory analysis by a grading system. Good acceptance was obtained with the bread prepared with 30% sesame flour + 70% wheat flour. Its external and internal appearance, as well as its organoleptic characteristics were close to the bread, with 100% wheat flour. Sesame flour at the 50% proportion gave a bread of medium quality. The protein mixtures of sesame flour and soybean flour were well accepted. Some of the panel members reported that it had a taste somewhat like integral bread.     

Evaluation of cookies enriched with corn germ and soy fiber

The objective of this study was to evaluate four cookie formulations which wheat flour was partially substituted by free-fat corn germ flour and/or soy fiber. Baking quality, protein, fat, ash, dietary fiber, hardness, color, Protein Efficiency Ratio PER and Apparent Digestibility in vivo were determined. A trained panel evaluated color, hardness and fracturability of cookies. Dietary fiber of cookies varied from 8.2 to 24.9% and protein from 11.3 to 12.7%. The source and amount of dietary fiber modified physical, sensory, and nutritional properties of cookies. Cookies formulated with 20% corn germ flour gave the highest PER, Digestibility Aparente in vivo, and acceptance by consumers. This study demonstrated the potential use of free-fat corn germ and soy fiber as functional ingredients.     

Chemical and sensory characterization of cakes enriched with dietary fiber and micronutrient for the elderly

This study presents the development of individual cakes enriched with dietary fiber (lupin and oat fiber), vitamins and minerals; as recent research has shown that the average daily dietary fibre intake of the elderly population in Chile is only 12 g. Each cake contains 4.8 g of dietary fibre and a 30% of the RDA of vitamins A, B1, B2, B6, B12, E, nicotinamide and folic acid, 40% of the RDA of vitamin D3, 15% of the RDA of calcium, 12% of the RDA of magnesium and 3% the RDA of zinc. Polydextrose and sorbitol were added to improve flavor and texture. Response Surface Methodology (RSM) was used for optimization, based on a two-variable composite design. Thirteen experimental runs were carried out, with polydextrose (1 to 40% based on flour content) and sorbitol (1 to 30% based on flour content) as independent variables. The response variable was sensory quality obtained by the Karlsruhe test. Sensory attributes of texture and overall quality showed a good fitting with high determination coefficients and were used for optimization. The optimized cake contained 11.5% polydextrose and 4.4% sorbitol (both based on flour content). Quality of the optimized product was controlled by means of physical, chemical, microbiological and sensory analyses. Overall sensory quality was 8.18 ("very good") and good quality and nutritive value were achieved. In an acceptance test carried out with 150 adults, 100% acceptability was obtained in the hedonic scale categories "like it" and "like it very much". A shelf life study performed with cakes packaged in polypropylene bags of 30 microns thickness indicated a shelf life of 13 days stored at room conditions (25 degrees C and 55-60% R.H.).     

Use of sunflower (Heliantus annus, L.) in human foods. II. Enrichment of sunflower protein concentrate with fish and sesame flour

The first part of this study revealed that a sunflower meal submitted to thermic treatment resulted in a protein of better quality when supplemented with lysine, while the meal not subjected to thermic treatment, supplemented with methionine, did not increase its nutritional value. These data indicated, therefore, that the limiting amino acid in sunflower meal is lysine, and not methionine. Based on these findings, and in order to confirm previous results, fish flour (high in lysine) and sesame flour (high methionine) were used to enrich the amino acid pattern of the sunflower protein concentrate. Three diets were thus prepared at the 10% protein level, containing: Sunflower protein concentrate which provided 70% protein, plus sesame flour (30% protein). Sunflower protein concentrate with 70% protein, and fish flour (30% protein). Sunflower concentrate with 70% protein, sesame flour with 20%, and fish flour with 10% protein. These following conclusions were derived on the basis of the analysis of these results: Supplementation of sunflower concentrate with 30% sesame flour does not producer a product of high nutritional value, once again indicating that lysine and not methionine is the limiting amino acid. Supplementation of the sunflower protein concentrate with fish flour (high in lysine content) presents a protein efficiency ratio (PER), practically equal to that of the casein pattern.     

Soy and corn flour precooked with microwaves and its use in the preparation of arepas]

Unhusked corn and soy grits were used as raw material, with a particle size ranging between 10 and 20 mesh (ASTM). The results obtained in this study reveal that microwave heating is effective in destroying the antinutritional factors present in soybeans. The trypsin inhibitor activity, in effect, was reduced to a 76% inactivation. The hemagglutinating titer was labile to the heating process, showing values of +8 to +3 for the full-fat soy flour and precooked soy flour, respectively. The quality of soy protein was measured by the protein efficiency ratio (PER) showing values of 2.63 for the precooked soy flour, and 2.46 to 2.21 for the precooked corn:soy blends (70:30 and 50:50). These uncooked blends present values of 1.17 and 1.04. The enriched corn:soy flour had a PER value of 1.60, in comparison to casein (PER = 2.90). The microwave heating improved the digestibility of the soy flour and blends. There were no significant differences (P less than or equal to 0.05) in relation to the functionality of the precooked flour and mixtures. The results obtained revealed that the applied process markedly improve the functional properties and nutritional value of the enriched flour, and of the "arepas" prepared from them.     

Evaluation of the partial substitution of precooked corn flour by rice flour in the preparation of arepas

The purpose of this research was to evaluate the effect of the partial substitution of rice by precooked corn flour, fortified or not with soy, on the organoleptic and nutritive characteristics of the arepas and on the expansion of the dough. Blends with 10, 20 and 30% of raw and precooked rice flours, and 8% soy flour were utilized. The results for arepas indicate that the partial substitution had no significant effect on the organoleptic characteristics nor nutritive value. The soy improved significantly the nutritive value. The expansion of the dough of the blends varied in respect to corn flour, without causing appreciable difficulty in the preparation of the arepas. The industrial precooked rice flour imparted great adhesivity, thus difficulty in the kneading, a fact which could lead to rejection by the consumer.     

Corn amino acid imbalance and the role of leucine excess

A study was conducted using two experimental models with weanling rats of the Wistar strain fed isocaloric diets containing 7% protein, Model I: two genetic varieties of maize were used; common corn (CC) or opaque-2-corn (M); and Model II: casein, 7% protein used without nicotinic acid in the diet in order to enhance the tryptophan limiting conditions like in the CC diet of Model I. PER, nitrogen balance, urinary urea and hepatic fat were determined. The results suggest that the imbalance of CC protein is related to lysine and tryptophan limitation, although the leucine excess content also plays an important role.     

Nutritional and sensory evaluation of macaroni supplemented with fish protein concentrate

The present work consisted of the supplementation of macaroni with fish protein concentrate (FPC) at the levels of 5, 10, 15, and 20% in relation to wheat flour. The FPC was obtained from eviscerated and deboned trairas (Hoplias malabaricus), using boiling ethanol as a solvent at a pH range of 5.5 to 6.0. The FPC showed desirable aspects such as bright color, no off-flavor, high levels of protein (84.3 g/100 g) and lysine (484 mg/g N) and low levels of fat (0.4 mg/100 g) and moisture (8.6 g/100 g). The macaroni became slightly dark in color with increasing additions of FPC. Nevertheless, the 20% level was the only one not accepted by the testing panel, in terms of color and flavor. Weanling Wistar rats were used in the biological assay to measure the macaroni protein quality at the different supplementation levels. Analyses of PER, NPR, NPU, digestibility and retained carcass N were carried out. The protein quality of the macaroni was improved by the addition of FPC. The level of 10% was similar to the casein and no subsequent improvement in the protein quality was notified with higher levels of FPC. Due to its high lysine content, the FPC is a promising supplement for cereals. From the nutritional and sensory aspects, the 10% level of FPC was the most satisfactory for macaroni supplementation.     

Distribution of tocopherols within the corn kernel

The concentration of tocols and tocotrienols in the germ, endosperm and pericarp of the corn kernel was determined after hand dissection of four dent corn hybrids—normal, early maturing, high oil and high lysine (opaque-2). Among these hybrids the germ fraction contained 70–86% and the endosperm fraction contained 27–115 of the tocopherols extracted from the whole grain. The endosperm fractions contain all of the measurable tocotrienols occurring in whole corn. In the four hybrids analyzed, the germ fraction contained 94–96% of thea-tocopherol extracted from the whole grain. Concentration ofa-tocopherol was the highest in the germ fraction of the opaque-2 hybrid.     

Flour of hard bean (Phaseolus vulgaris) in the preparation of bread]

In order to utilize hardened beans, we proposed to find the method most indicated for the preparation of bean flour to determine their nutritional value, and to make bread of high industrial, nutritional quality, and good sensory characteristics, using blends of bean and wheat flours. Two types of flour were prepared, testing four soaking temperatures (22, 30, 40 and 50 degrees C) and two methods to remove the testa (under moist and dry conditions). At laboratory level, the dry testa removal method gave the best flour yields (mean = 85.8%) and the highest protein content (mean = 23.7%). Comparison between soaking temperature at 30 and 50 degrees C was not significant (alpha = 0.05). At pilot plant level, with soaking at 50 degrees C the flour yields were 58.0% for moist testa removal (H1) and 74.0% for dry removal (H2), with a protein content of 22.6% for H1 and 23.0% for H2. The H1 and H2 flours were added to wheat flour at 5, 10 and 15% for bread making. The addition of 5.0% gave breads with similar protein content and sensory characteristics to those of the control, wheat. A diet based on bean-flour bread resulted in greater weight gains than that with casein for gold hamsters. The study also demonstrated the importance of heat-treating of the bean flours, because when flour without previous heat treatment was administered, the animals lost weight and died. This effect was overcome by the process of baking the flours at 140 degrees C for four hours.     

Evaluation of the protein quality of legume flours obtained by roasting in heated beds

Roasted flours from cowpea, canavalia and washed lupin were prepared by a thermic treatment in fluid sand beds at 150, 200 and 250 degrees C for 2.0 and 2.5 minutes, followed by dehulling and grinding. A flour produced by pressure cooking at 121 degrees C for 30 min followed by drying was used as reference. The flours were evaluated through residual levels of antitryptic activity, tannin content, available lysine, NPR and protein digestibility. The roasting and the pressure cooking processes increased NPR values. Nevertheless, the NPR values of all legume flours were significantly lower than the NPR casein values. The roasting process carried out under the conditions indicated inactivated trypsin inhibitor activity significantly. A small decrease in tannin content was also observed, with small insignificant changes in available lysine. The protein digestibility of all products was high with lupin, digestibility being equal to that observed for casein. The roasting process in a fluid granular bed allows the production of products of acceptable protein quality with low levels of antiphysiological factors.     

Development of bakery products for greater adult consumption based on wheat and rice flour

The present investigation was developed as a contribution to Guatemalan's elderly food and nutrition. Its main objective was to evaluate the chemical, nutritional and sensory quality of bread prepared from the partial substitution of wheat flour with rice flour. Wheat flour substitutions with rice flour in the order of 15, 20, 30, 40, 50 and 60% were evaluated. Differences with the control (100% wheat bread) were found during the process of preparation, as well as texture, volume, height, weight and specific volume. Important effects in dough handling were noted specifically in the 40, 50 and 60% rice bread. Thus, a sandy texture was found in breads of higher rice levels. The bread protein quality increased with the level of substitution; however the protein quality difference between the wheat bread and the bread with 60% rice flour did not achieve statistical significance. Based on a statistical analysis of the physical properties the bread with 30 and 40% rice flour was selected, and through a preference test between these last two, the 30% rice flour bread was selected as the sample best suited to the present study's purposes. This bread was not different to wheat bread in many nutritional parameters, although in others it showed to be superior. Each serving size of bread has a weight of 80 grams (2 slices) that contributes adequate quantity of calories, protein and sodium, although a little less dietary fiber than 100% wheat bread.     

Optimization of formulations for dietetic pastry products

Optimized formulations of dietetic pastry products such as cake and sponge cake premixes were formulated using the surface response methodology. % Emulsifier agent and baking time were the selected independent variables for cake, as well as % emulsifier agent % chlorinated flour the variables selected for sponge cake. Three different level of each variable summing up thirteen experimental formulae of each product were assessed to optimize the variables that could have some influence in the sensory characteristics of these dietetic products. The total sensory quality was determined for both dietetic products using the composite scoring test and a panel of 18 trained judges. Looking at the contour graphic and considering economic aspects the best combination of variables for cake formulation was 2% emulsifier agent and 48 minutes for baking time, With respect to sponge cake, the best combination was 6% emulsifier agent and 48% chlorinated flour. Shelf life studies showed that both dietetic formulations remained stable during storage conditions of 75 days at 30 degrees C. During this period, significant differences in sensory characteristics were not found (p < 0.05). Data of peroxide values were kept under the critical value reported for detection of organoleptic rancidity. Reported values of hedonic test showed that these dietetics pastry products had good acceptability, and open up marketing opportunities for new products with potential health benefits to consumers.     

Soy flour and grits for use in food products

Processing alternatives enable the soybean processor to manufacture soy flour products which vary in fat content, granulation and degree of heat treatment. By controlling these variables, the processor is able to regulate the nutritional value and functional properties of these products. The application of soy flour products is dependent upon their functional properties, nutritional value and low cost. Currently, the major markets for soy flour and grits are in pet foods and animal feeds, cereal based foods and ingredients, meat based foods, and as a substrate for refined protein products such as the textured vegetable proteins, soy protein concentrates, isolates and hydrolysates. These soy protein products are generally marketed as functional and nutritional substitutes for meat, milk and egg protein. For example, soy flour is a functional replacement for milk in many cereal-based foods, e.g., bread, and also enhances the nutritional value of the cereal protein by supplying lysine to the formulation. The United States government has pioneered the development and marketing of protein-enriched, cereal-based foods designed to combat worldwide starvation. The government has directly supported the research and development of corn and wheat-based food substrates supplemented with soy flour, and has purchased over one billion pounds of these products since 1966 for worldwide distribution. One of 21 papers presented at the Symposium, “Oilseed Processors Challenged by World Protein Need,” ISF-AOCS World Congress, Chicago, September 1970.     

Elaboration of a dried-salted and smoked product using aquaculture species

The purpose of this work was to adapt the procedure developed at the Instituto Nacional de la Nutrición Salvador Zubirán (INNSZ) for the conservation of the sardine to aquaculture species such as carp (Ciprinus carpio) and tilapia (Tilapia sp). The mixtures were designed on the basis of the chemical score method. The preparation of the patties included different fish presentations, and two methods were evaluated in order to obtain fish pulp. In the formulation of the final product, defatted soy, maize and wheat flour were included, as well as three different mixtures of condiments, which were then compared to the original formulation based on sardine. The raw materials and final products were subjected to sensory evaluation and to a shelf-life study. The results indicated that for these species, to obtain the fish pulp it is necessary to include one phase of the procedure, which can be manual or mechanical, because there are no significant differences between them. The formulations selected were: flour corn (10%)--flour soy (30%)--carp (60%), and flour corn (10%)--flour soy (22%)--tilapia (68%). In both cases the condiment mixture was eliminated, and only common salt was used. The protein content was of 40g/100g of the dry product, with a minimum shelflife of 12 weeks at room temperature (22 degrees-23 degrees C). During this period no rancidity developed, the product was microbiologically adequate for human consumption, and proved to have a higher sensory acceptance than sardine patties.