No abstract

Germinated wheat and barley increased significantly (P < 0.05) in % Relative Nutritive Value (RNV); the increase in % RNV was highly significant (P < 0.01) for germinated rice. The increase in available lybine was highly significant (P < 0.01) in germinated wheat, barley, oats and rice. Natural lactic acid fermentation increased the % RNV significantly (P < 0.05) for wheat, barley and rice and significantly (P < 0.01) for millet and maize. The available lysine content increased significantly (P < 0.05) in fermented oats, rice, millet, and maize but the available lysine increase was highly (P < 0.01) signiticant in fermented wheat. Both germination and fermentation had equivalent effects as procedures to improve the protein quality of cereals.

Natural lactic acid fermentation of corn significantly reduced phytate levels and thus increased the amount of Fiske-Subbarow positive phosphorus (free). Sixteen bacterial strains isolated from a natural lactic fermentation of corn meal had active phytases.

Heat-induced dormancy was observed when spores of two strains of Bacillus stearothermophilus were heated in distilled water at 80, 90, and 100 C. At temperatures above 100 C, true activation occurred; however, maximal activation was not achieved until temperatures of 110 to 115 C were employed. A heat treatment of 115 C for 3 min was required to induce maximal activation in one suspension of strain 1518 spores, whereas a heat treatment of 110 C for 7 to 10 min was adequate for the other suspension of strain 1518 spores. Spores from both strain M suspensions required heat treatments of 110 C for 9 to 15 min for maximal activation. The degree to which the spores could be activated was strain dependent and variable among spore suspensions of the same strain. The germination and outgrowth of all spores, regardless of strain and suspensions source, were significantly reduced when the spores were heated in M/120 phosphate buffer at maximal or near maximal activating temperatures. It was suspected that phosphate lowered the heat resistance of the spores to the extent that the heat treatments were lethal to a portion of the populations. The association of heat with spore germination has a unique place in the biology of the bacterial endospore. Curran and Evans (1944, 194.5) were the first workers to demonstrate systematically that sublethal heat (62 to 95 C) could induce dormant spores to germinate. For most of their work, thermotolerant, mesophilic strains were used; however, selected thermophilic strains were also investigated, including strain 1518 of Bacilius stearothermophilus. This thermophile is of particular interest to the food processor and food microbiologist because the spore form is extremely heat resistant and the vegetative form, which is capable of growth at temperatures of 70 C or slightly higher, is responsible for flat sour spoilage of low acid, canned foods. The first reference to activation of endospores at temperatures greater than 100 C was made by Brachfeld 1 Contribution from the Missouri Agricultural Experiment Station. Journal series no. 2383. Approved by the Director.

A natural lactic fermentation of ground grain sorghum produced significant increases (P < 0.001) in available lysine/leucine, isoleutine, and methionine. The protein quality, expressed as relative nutritive value, increased significantly (P < 0.001) as a result of fermentation. Niacin and thiamin increased significantly (P < 0.001) and riboflavin also increased (P < 0.05) during the fermentation. Protein and carbohydrate appeared to be more available after the fermentation than before the fermentation. Although the fermentation produced increased availability of nutrients, it did not produce change in the proximate analyses.

Cowpeas and chickpeas were allowed to undergo natural fermentation for 4 days at 25°C. The microorganisms isolated from cowpeas and chickpeas were Lactobacillus casei, L. leichmanii, L.plantarum, Pediococcus pentosaceus and P. acidilactici. Lactobacillus helveticus was found in chickpeas only. This makes the fermentation chiefly lactic acid. Pathogenic organisms were not found in the system. Relative nutritive value (RNV) and limiting amino acids increased significantly (P < 0.05) in the fermented beans. Niacin decreased significantly (P < 0.05) in both of the fermented beans. Thiamine decreased in fermented chickpeas while riboflavin increased in fermented cowpeas. Trypsin inhibitor decreased significantly (P < 0.05) in both of the fermented beans. Raffinose was eliminated in cowpeas and decreased significantly (P < 0.05) in fermented chickpeas.

Corn and sorghum seeds were germinated at 25", 30" and 35'C. Germinated seeds of both cereals had increased relative nutritive values (RNV) and increased levels of lysine, methionine, and tryptophan when compared to nongerminated seeds. The RNV's of the nongerminated corn and sorghum meals were 66.8 and 55.5% respectively while the RNV's of the germinated corn and sorghum were 99.5 and 62.9% respectively. The highest RNV for corn occurred after 4 days at 25"C, 2 days at 30°C and 3 days at 35°C. For sorghum, highest RNV was attained when the seeds were germinated for 5 days at 25"C, 6 days at 30°C and 3 days at 35°C. The highest RNV value achieved by germinating corn was 99.5%, whereas the highest for sorghum was 78.3%.

Agidi, a Nigerian food made from corn, was prepared by the traditional Nigerian method and by a modified procedure in which fermented corn was used. The fermented agidi (with or without pH adjustment of the corn) was significantly higher (P < 0.05) in tryptophan and lysine than the nonfermented agidi. Sensory analyses indicated that flavor for the fermented (either pH adjusted or not) had a score greater than average (scale of 1 to 5, with 5 being the highest on the desired scale). However, since total sensory score (total points for color, firmness, acidity and flavor) was less than the traditional agidi, blending of the two is indicated for best acceptance and nutrition.