Authors have felt a great interest in the plant biological actions with relation to acylamino acids.
However acylamino acids as the natural products were extracted from the Natsumikan juice for explanation of a role in the plant. Ionexchange chromatography (Amberlite IRA-400[R₂CO^-₃], Amberlite IRC-50 [H⁺], Dowex 50-X 8 [H⁺]) and paper partition chromatography (BuOH : AcOH : water : 4: 1: 5 v/v) used authentic reagents were carried out beforehand, then natural acylamino acids were separated respectively.
Quantitative analysis of saponified acylamino acids were carried out by an amino acid autoanalyzer.
As the results, acylamino acids that connected with amino groups of amino acids such as glycine, glutamic acid aspartic acid, alanine, serine, proline, lysine, threonine were clearly recognized the existence in the supernatant fraction, whereas the fatty acid portions would identify after this.

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The nutritive values of chlorella cells (chlorella regularis) grown under heterotrophic condation was studied by rats feeding tests.
Growing male rats had been fed with containing 7.5% or 10% protein of chlorella cells for 30 days, and feed efficiency was calculated from their growth rate and food consumption. True digestibility and biological value of the protein in chlorella cells were determined by the nitrogen balance method with growing female rats fed a 5% or 10% level of protein diets.
The results were followings.
1. In terms of growth rate and feed efficiency in rats, nutritive value of chlorella cells was nearly equal to those of milk casein and Kinako.
2. True digestibility of protein in chlorella cells and whole egg were 80.4% and 89.3%, respectively, at 5% level of protein intake, and 82-84% and 94.3% respectively, at its 10% level, their biological values were in the range 55 to 70 and 80.4 respectively. As a results of these experiments, though true digestibility was higher than that of already reported, there was no differences from biological value.

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Formaldehyde was induced from a certain precursor by acid-hydrolysis or by thermal degradation during the official steam distillation. In order to determine an accurate amount of formaldehyde spontaneously involved in the foodstuffs, the authors have also investigated on optimal conditions for the acetylacetone reaction. Thus, they found that only 3, 5-diacetyl-1, 4-dihydrolutidine was almost completely extracted with n-butanol or isoamylalcohol and that other yellow pigments in the tissues were not transferred into the organic solvent layer. The formaldehyde content in fresh vegetables, mushrooms and their dehydrated products was estimated according to the acetylacetone method via extraction with n-butanol.

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When both purified γ-glutamyl transpeptidase and cysteine sulfoxide lyase were added to the homogenate of Shiitake mushroom, formaldehyde amounted to twice that found in the control. On the other hand, the enzymatic formation of formaldehyde was terminated in the presence of either a serine-borate mixture or hydroxylamine. It has been proved that a significant amount of formaldehyde is liberated from lentinic acid and its component “des-Glu-lentinic acid” by the action of flavor enzymes. Des-Glu-lentinic acid, a new sulfur-containing amino acid, which served as a specific substrate for C-S lyace, evolved a maximum amount of formaldehyde in the range of pH 8 to 9. A C-S lyase found in Lentinus edodes showed a high affinity towards the amino acid giving an apparent Michaelis constant of 60 to 70 μM. Experimental results evidenced that the spontaneous evolution of formaldehyde in L. edodes is entrusted to the pathway of the lenthionine production from lentinic acid.

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Several workers have studied the effects of rancid oils such as autoxidized or oxidatively polymerized oils on cholesterol metabolism in rats, however, little knowledge has been obtained. In the present study, the authors examined the influence of rancid oils (autoxidized, thermally oxidized, thermally polymerized oils) on plasma and liver cholesterol levels. Rats were fed ad libitum for 4 weeks with diets which contained 4% rancid soybean oils with or without cholesterol.
The results obtained were as follows :
1) Significant differences of plasma cholesterol levels between groups fed fresh oil and the corresponding oxidized or polymerized oils were not observed.
2) Liver cholesterol of rats fed thermally oxidized oil and thermally polymerized oil decreased.
3) Percentage of C_{18: 2} acid in liver lipids fed highly autoxidized oil decreased, but the component of fatty acid in liver lipids fed other rancid oils was similar to those of rat fed fresh oil.

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The influence of Konjac flour (KF), crude Konjac mannan prepared from the tubers of Amorphophallus konjac K. Koch (Araceae), on the endogenous cholesterol metabolism in rats was studied.
1) The high levels of serum and liver cholesterol in the rats preliminary fed a hypercholesterolemic diet containing 1% cholesterol and 0.25% bile acids for 10 days were reduced to normal by changing that diet to cholesterol-free diets supplemented with or without KF, and their reduction rates were especially stimulated when shifted to a cholesterol-free diet with 5% KF.
2) The in vivo and in vivo incorporations of acetate-2-¹⁴C into liver cholesterol and the in vivo degradation of cholesterol-26-¹⁴C to the expired CO₂ in rats fed a cholesterol-free, KF diet for 10 days were examined.
The biosynthesis of cholesterol was substantially higher in the KF diet groups in vivo and in vitro than the control diet group, while degradation was not accelerated by the administration of KF. However, no significant alterations in the levels of both serum and liver cholesterol were shown in rats fed the KF diet as compared with the control group.
3) From these results, KF is inferred to stimulate the excretion of the undegraded liver cholesterol into bile, or subsequently into feces. Possible roles of the hypocholesterolemic activity of KF in relation to the intestinal reabsorption of endogenous enterohepatic circulating cholesterol or bile acids were also discussed.

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Sorbic acid in foods is usually determined by ultraviolet absorption or colorimetric methods. And the latter is valuable for screening test.
Some components in ginger and a few spices gives color reaction like sorbic acid by colorimetric method with p-hydroxybenzaldehyde. Therefore, the method based on this reaction bring about an error of the content in foods containing ginger or a few spices. Three colored spots like sorbic acid in ginger were found by thin layer chromatography.
On the other hand, colorimetric method with thiobarbituric acid for sorbic acid in foods hardly gives an error of the content, even if applied for ginger and spices.

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