In the previous report, we have described the effects of monoglycerides against the inflation spoilage. Here, the effects of short chain fatty acids and some surfactants are described. Lauric acid had the highest effect to suppress the gas production among fatty acids tested, and it suppressed the gas production perfectly at the concentration of 0.03%. There were some surfactants which had the suppressive effect at 0.1%. When n-capric acid or monocaprin was combined with them, the suppressive effect was usually higher than that of n-capric acid or monocaprin. But tween 80, span 80 and monoolein contrarily reduced the suppressive effect of n-capric acid or monocaprin. On the addition of any polysaccharide or any protein also reduced the effect.

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The pulp refuse of citrus fruits was produced as a by-product from their juice e xtraction process. To increase in their new uses, citrus dietary fiber (CDF) was prepared by washing them in hot water repeatedly. Four kinds of dietbry fiber (DF), which were CP (cellulose powder from cotton cellulose), WF (Avicel RC-N 81 from wood) and PF (Fiber P-1 f rom potatoes) on the market and CDF, were examined on their physical and chemical properties and on their preventive effects against amaranth toxicity caused by feeding of a diet containing 5% amaranth. The diets used for rats in this experiment were as follows. They were B (basal diet), A (B diet+5% amaranth), A1 CDF, A3 CDF, A5 CDF, A10 CDF, A3 CP, A5 CP, A10 CP, A5 WF (A diet+5% WF) and A5 PF (A diet+5% PF) diet. A1 CDF, A3 CDF, A5 CDF and A10 CDF diet were made by addition of 1, 3, 5 and 10% CDF to A diet and A3 CP, A5 CP and A10 CP diet were similarly prepared by additi on of 3, 5 and 10% CP to A diet. (1) Both WHC (water holding capacity) and SV (settling volume in water) values of four samples became larger in order CDF, PF, CP and WF. There was high correlation (Y=0.96 x-1.66, r=0.98) between WHC and SV of each sample. Their chemical compositions were rich in cellulose and pectic substances and poor in hemi chemical compositions were rich in cellulose and pectic substances and poor in hemi reduction in the growth rate of rats. The rats fed on A1 CDF, A3 CDF, A3 CP and A5 CP diet were not able to gain satisfactorily their body weight by diarrhea. The rats fed on A5 CDF diet were considerably restored to gain their body weight without diarrhea. The rats fed on A10 CDF diet grew up normaly as same as the rats fed on B diet. The rats fed on A10 CP diet grew up next to the rats fed on A5 CDF diet. The preventive effect of CDF against amaranth toxicity was recognized at the additional level of 5% CDF to A diet. (3) The rats fed on A5 CDF diet grew up next to the rats fed on B diet and the rats fed on A5 PF diet next to A5 CDF rats and they were suffered from a little amaranth tox icity in comparison with the rats fed on B diet. The rats fed on A5 CP or A5 WF diet were unable to increase satisfactorily their body weight by diarrhea caused by amaranth toxicity.

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A HPLC method for riboflavin determina-tion in tea was developed. An assay solu-tion was prepared as follows: 2g of tea wasextracted with 40ml of 0.1 N HC1 in boilingwater for 30min. The extract was incubatedat 48°C for 3h after addition of 5ml of 1MNaOAc and 5ml of 6% taka-diastase, thencentrifuged at 3000rpm for 10min. Thesupernatant was filtered using a 0.45μmfilter, and 90μl of the filtrate was subjected to HPLC. The HPLC system consisted of aODS-120A (4.6mm_φ×25cm) column, a sol-vent system of H2O-CH3CN-ACOH (88.5:11:0.5) and a flow rate of 1.0ml/min. Quantity of riboflavin was based on fluorescence, excitation at 360nm, and emission at 500nm. The riboflavin recovery was 96.2%.

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Ascorbic acid (AsA), oxidized specifically by ascorbate oxidase (ASOD) was determined by the measurement of the decrease in dissolved oxygen (DO) in the water sealed, small reaction system of a Clark oxygen electrode. The effects of temperature, pH and buffer concentration of reaction mixture on the DO uptake (mM AsA equivalent) were examined. The most suitable AsA analysis with the oxygen electrode was proved. So far as the analysis for AsA standard solution, a linear relationship was found between the DO uptake and AsA concentration. Furthermore AsA concentration was twice DO uptake, thus making it possible to determine AsA without using a calibration curve. The content of AsA in orange juice sample determined by the present method has a good comparability to that of the 2, 4-dinitrophenylhydrazine (DNP) method and high performance liquid chromatography (HPLC), and the recovery rate of AsA added to the orange juice ranged from 97 to 105%. Thus, this method could be available for the rapid and accurate determination of AsA contents in foods.

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The analysis of AIS (alcohol insoluble solids) in vegetables by a sequential extraction procedure, in which pectic materials were considered important, was carried out for fractionation of dietary fiber constituents. AIS of the samples were fractionated by se quential extraction following pectinase, pronase and α-amylase (pancreatin) digestion (F-1-F-III), delignification (by chlorine-ethanolamine method, F-IV) and alkali extraction (with 10% N_aOH, F-V) were then carried out to finally obtain an alkali insoluble residue which was barned to obtain the ash content (F-VI). To investigate the selective and quantitative extraction of AIS components by enzyme digestion, delignification and alkali extraction, histochemical and analytical tests were carried out in preliminary experiments. The values obtained were adequate and reproducible when considered in reference to six kinds of vegetables.

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Buffer capacity (β) of cow's milk was measured in the range of pH 3 to 11 with a βtitrator.β-pH curve of the milk showed strong buffer capacity in the range of pH 3 to 6 and 9 to 11, and also showed two peaks at about pH4 and 6.From the data of pK values of the weakelectrolytes in the milk, it was presumed thatorganic acids conhribute to the buffer capacityat about pH 4, and high buffer capacity at aboutpH 6 would be due to His, Cys residues, phosphoric, carbonic and citric acids.In the range of pH 9 to 11, the high buffercapacity would arise from Lys, Cys, Tyresidues and carbonate.Buffer capacity of whey was much smaller thanthat of milk, in the range of pH 3 to 6By inoculation of L. bulgaricus, the peak atpH 4 was increased.Buffer capacity of the dialyzed milk was founddecreased by about half of the original one inthe whole pH range and, therefore, it wasmilk respectively contribute to about one half of the buffer capacity of the milk.The colostrum showed twice larger buffer capacity than the normal milk and gradually decreased and reached to the normal value fo milk after about 10 days.

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(1) The compositions of carotenoid in cultivars 'Toi' and 'Tanaka' at the fu lly mature stage were investigated by TLC method. The total carotenoid contents in the peel and the pulp of 'Toi' were lower than those of 'Tanaka'. It could be considered that the light color of 'Toi' was attributed to the lower carotenoid contents. The main carotenoids in both the peels were 61% and 87% in β-carotene, 3% and 8% in cryptoxanthin, and 21% and 2 % in lutein for 'Toi' and 'Tanaka', respectively. The carotenoids in the pulp wer e mainly composed of β-carotene 32% and 55% and cryptoxanthin 52% and 25% for 'Toi' an d'Tanaka', respectively. (2) The compositions of carotenoid were studied in the peel and the pulp of 'Tanaka' during maturation. The carotenoid content in the peel decreas ed with the decrease in chlorophyll in the peel. It increased rapidly when the peel color ch anged from green to yellow, and subsequently the color turned yellow-orange. Lutein which w as a main carotenoid at green stage decreased gradually as color changed. On the other han d, β carotene which was secondary in quantity at the immature stage showed similar ch anges in the content as total carotenoid contents and it became a predominant carotenoid at the mature stage. The change of β-carotene in the pulp showed a straight rising cur ve with no decrease during maturation. The cryptoxanthin content was at a low level in the immature stage, but it rapidly increased and it became a main component in the fully matu re stage.

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Inhibitory activities of proteins originated from plants and animals were estima ted for lipase. All proteins tested inhibited Rhizopus delemar and Candida cylindracea l ipases, but they did not inhibit porcine pancreatic lipase much in contrast. Homo-poly-amino acids were employed to simplify the reaction system and consequently make clear the me chanism of the lipase inhibition by proteins. Simplified interfacial studies were also p erformed to explain the inhibitory mechanism. The hydrophobicity and the conformational stru cture of each protein were concerned with the inhibitory activity. It is probable that th e protein inhibits the lipase activity by the physical separation of lipase from its subst rate.

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A bitter peptide fraction from the peptic hydrolysates of soybean protein was treated with crystalline wheat carboxypeptidase. The bitterness of the bitter fraction lessened with an increase in free amino acids and finally disappeared. The enzymatic hydrolysate obtained from the digest of the bitter peptide fraction by wheat carboxypeptidase was chromatographed on Sephadex G-15. Amino acid compositions of each eluate fraction were determined by an amino acid analyzer. When the release percentage of total free amino acids was approximately 27%, those of hydrophobic amino acids with a Δf value (cal/mo1)>1600 were 27-63% except for proline, and amino acids with a Δf value<1600 had a tendency to be released less than hydrophobic amino acids. The wheat carboxypeptidase seems to have an ability to eliminate bitter taste in enzymatic hydrolysate by releasing hydrophobic amino acids from bitter peptides.

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The effects of ultraviolet (UV) irradiation upon the thermal gelation of meat pastes from sardine, hake muscles were examined by means of heating temperature-jelly strength curves (30, 40, 50, 60, 70, and 80°C). The UV irra diation (5000μW/cm², 15min) applied to the raw meat pastes revealed an enhanced effect on the jelly strength value of the paste after heat treatment. While the jelly strength of the pastes obtained by UV irra diation appeared to decrease with longer heating time at 60°C for sardine, and at 40°, 50°, and 60°C for Alaska pollack and Chile an hake, the values were always higher than those of the non-irradiated pastes. From the UV intensity-the thermal gelation cur ves, it was found that the jelly strength at 70°C rapidly increased in the range of about 3000 to 6000μW/cm² UV for sardine, and in that of 4000 to 7000μW/cm² UV for Alaska pollack.

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