The viability, chemical composition and internal microflora of frost damaged soybeans

Abstract

Summary Seven composite samples of Minnesota grown soybeans and seven individual lots of Illinois soybeans of the 1942 crop containing varying percentages of immature and frost‐damaged seeds were subjected various analyses. Increased damaged‐seed content was accompanied by a marked decrease in viability and by increases in phosphate acidity, amino‐acid acidity, nonprotein nitrogen, reducing sugars, and in the internal aerobic microfloral content of the seeds. Proximate composition of the samples within each series showed little variation. In the Minnesota series, crude fiber content slightly decreased with increasing damage but the total digestible nutrients values were essentially similar for all samples. The most severely damaged samples in each group were slightly the lowest in test weight per bushel and oil content and were the highest in oil acidity. In the Minnesota series, the iodine value of the oil tended to increase slightly with increasing damage; this is attributed to the fact that the most severe frost damage occurred in growing areas which normally produce oil of high iodine value.

Effect of Freeze Damage on Soybean Quality and Storage Stability

“…Oil content Prior to storage, freeze-damaged samples of both the Williams and Clark 63 varieties, had slightly lower oil percentages than control samples of the same variety. This would confirm data from Milner et al (1943) which showed that as the number of freeze-damaged seeds in a sample increases, the oil percentage decreases. However, none of the samples showed a statistically significant change in oil percentage during storage.…”

“…Most of the reported occurrences of freeze damage are in the northern soybean producing states. Milner et al (1943) (1980) to the extent that in some samples 55% of the beans were green and shriveled. Sanders (1946) reported that freeze damage increased the normal chlorophyll content of the crude oil a hundred fold.…”

“…Sanders (1946) reported that freeze damage increased the normal chlorophyll content of the crude oil a hundred fold. Milner et al (1943) and Tervet (1944) concluded that freeze-damaged soybeans were more likely to be infected by fungi and bacteria than nondamaged soybeans. Milner and Geddes (1946) explained that freeze-damaged seed coats are ruptured which encourages mold mycelial penetration and mold growth, and speculated that the fungal lipase produced by mold was responsible for high levels of free fatty acid in the crude oil.…”

Changes in Peroxidase Activity During the Development and Processing of Phaseolus vulgaris cv, Haricot Seed

“…Melvin et al (1953) also found that as the proportion of damaged frozen bean seeds increased, so did the free fatty acid content of the crude lipid. Milner et al (1943) reported that as the percentage of damaged seeds in a freezestored sample increased, there was a corresponding increase in non-protein nitrogen and reducing sugars. These increases were suggested to be the result of stimulated enzyme activity in response to the freezing process.…”

Storability of Frost-Damaged Canola

“…1D-F (Mills and Sinha 1980 (Mills, Van Caeseele and Daun, in prep . ) , destroyed the integrity of immature cells permitting increased leakage of electrolytes and also may have increased seed enzymatic activity (Milner et al 1943). …”