Effects of soybean genotype and growing location on oil and fatty acids in tofu.

Soyfood products like tofu are becoming popular among American consumers due to health benefits. In order to increase production to meet consumer demands, it is imperative that factors that effect quantity and quality of tofu be characterized. The present study was conducted to determine the effects of soybean genotypes and growing locations on contents of oil and fatty acids in tofu which was prepared from twelve soybean genotypes (BARC-8, BARC-9, Enrei, Hutcheson, MD86-5788, Nakasennari, S90-1056, Suzuyutaka, V71-370, V81-1603, Ware, and York) grown at three southern U.S. locations (Huntsville, Alabama; Princess Anne, Maryland; and Petersburg, Virginia) during 1995. The results showed that tofu quality was determined by the soybean genotype. The tofu made from seeds of high seed-protein and low seed-oil genotypes (BARC-8 and BARC-9) resulted in tofu with low contents of oil (15.8 and 11.3 g/100g, respectively) and total saturated fatty acids (2.59 and 160 g/100g, respectively). Tofu made from seeds of conventional grain type genotypes, such as Hutcheson, resulted in higher oil (24.0 g/100g) and total saturated fatty acids (3.80 g/100g) contents in tofu. Effects of growing environment on contents of oil were not significant but tofu made from seeds grown in Alabama had significantly higher content of total saturated fatty acids (3.50 g/100g) as compared to that made from seeds grown in Maryland (2.88 g/100g) or Virginia (2.96 g/100g). Tofu made from seeds of large and medium-seeded genotypes had higher contents of total monounsaturated fatty acids in tofu as compared to that made from small-seeded genotypes. Highly positive correlation existed between contents of oil, 18:1, 18:2, total saturated, and total unsaturated fatty acids in the seeds and their contents in the tofu (+0.80, +0.75, +0.79, +0.62, +0.68, respectively). These results indicated that tofu quality is governed by soybean genotype, seed size and growing location.

Seed characteristics and nutrient composition of selected beans (Phaseolus vulgaris L.) with different ozone tolerance.

Ozone sensitivity, nutritional quality, seed characteristics, and growth habit of beans (Phaseolus vulgaris L.) were evaluated in two separate experiments. In the first experiment the data showed a significant variation among 34 bean accessions for ozone sensitivity following acute exposure of 18-day-old plants to 0.6 microliters/l O3 for 2 hours under environmentally controlled greenhouse conditions. PI-163579, PI-169735, PI-171790, PI-176684, PI-201374, PI-310711, PI-345576, PI-370569, PI-379435, and PI-414831 were identified as tolerant to acute ozone exposures. Protein, oil, starch, sugar, and ash contents in the seed of selected germplasm were determined and no correlation was found between these components and ozone sensitivity. Seed size and growth habit varied considerably among the 34 accessions but were not correlated to ozone sensitivity. In a second experiment, ten accessions, selected from the tolerant ones identified in the first experiment, were subjected to chronic ozone exposure in open-top chambers at 0.04 and 0.08 microliters/l concentrations for 7 hours/day 44 days after transplanting. Based on foliar injury and yield reductions, only PI-370569 and PI-414831 were tolerant to prolonged ozone exposure (0.08 microliters/l). A significant positive correlation (r = 0.83) existed between foliar injury rating from chronic treatments involving 0.04 and 0.08 microliters O3/l and acute exposure (0.6 microliter O3/l/2 hours). The data indicated that acute ozone exposure can be used to initially screen a large number of bean accessions, however, this is an imperfect indicator of ozone sensitivity with chronic exposure.

Screening soybean (grain and vegetable) genotypes for nutrients and anti-nutritional factors.

Fifty six genotypes of grain-type soybean and 17 genotypes of vegetable-type soybean collections were analyzed for protein and oil content, trypsin inhibitor, and lipoxygenase activities. The protein and oil content ranged from 36.9 to 47.9% and from 13.3 to 23.0% for different accessions in grain- and vegetable-type soybeans, respectively. Trypsin inhibitor and lipoxygenase activities ranged from 22.0 to 47.0 trypsin inhibitor units/mg meal and from 482 to 6265 lipoxygenase units/min/mg meal for grain- and vegetable-type soybeans, respectively. Significant correlations (r = -0.62 and -0.52, P less than 0.05) were found between protein and oil, and between protein and trypsin inhibitor. A significant positive correlation (r = 0.42, P less than 0.05) was also calculated for oil and lipoxygenase activity. Several genotypes of soybean and vegetable soybean (plant introductions 423905, 417330, 417223, 171451, 200506, 200523, 417124, 227687, 203402, 445842, 203399, 423852, 416771, FC 31927, Avoyelles, and Sooty) showed good nutritional potential and may be useful in a breeding program to improve the nutritional quality of soybean. Screening for essential amino acids, fatty acids, and trace minerals for selected genotypes is underway.

Nutrient composition and anti-nutritional factors in selected vegetable soybean (Glycine max [L.] Merr.).

The genetic variation in the nutrient composition and anti-nutritional factors of 17 vegetable soybean genotypes were determined and a wide variation in protein %, total phosphorus (TPi) and available phosphorus (AP) was found among these genotypes. Variations in Ca, K, Fe, Mn, and Cu were also documented. Variation was also found for trypsin inhibitor (TI) activity and Phytate (PA) content. A highly significant and negative correlation (r = -0.533, P less than 0.01) was observed between TI and total protein. Strong positive correlation (r = 0.90) was also found between TPi and AP. Several genotypes (Sooty, Emperor, Wilson-5, PI 416771, PI 417322) showed good nutritional potential and can be used in the breeding program. High protein %, TPi, and minerals are desirable qualities for vegetable-type soybeans that make it as food with high nutrient density. Studies on the nutritional evaluation of immature vegetable type soybean seeds at different reproductive stages are also underway.

Inheritance of ambient ozone insensitivity in common bean (Phaseolus vulgaris L.).

The inheritance of ozone (O(3)) insensitivity in common bean (Phaseolus vulgaris L.) was evaluated using F(2) and F(3) populations under ambient conditions. This study was conducted over two growing seasons (1987, 1988) at Virginia State University, Randolph Research Farm, Petersburg, Virginia. Two populations were obtained by crossing insensitive plant introductions with sensitive commercial cultivars. Ratings on the scale of 1 to 5 (1 = 0 to 20% leaf injury, 2 = 21 to 40%, 3 = 41 to 60%, 4 = 61 to 80%, and 5 > 80%) were made on 160 F(2), F(3) progenies, and parental lines. Population mean injury ratings were recorded and estimates of genotypic, environmental, and phenotypic variances were computed. Estimates of heritability in the broadsense and of genetic advance were calculated for each population using F(2) and family component variance methods. Population means of the F(2) and F(3) progenies were not significantly different from their mid-parent values, suggesting that genetic variance was primarily additive. Broad-sense heritability estimates using F(2) variance method ranged from 51.4 to 70.5% and using family component variance method ranged from 62.1 to 75.6%. In this study, the computed genetic advance values closely parallel those of heritability estimated values. The high heritable nature of insensitivity would indicate that effective levels of insensitivity could be transferred to agronomically superior cultivars in a relatively short time.