Corn oil was emulsified with aqueous solution of fifteen different amino acids and glucose by the use of Tween 80 as a emulsifier. The oil was thermally oxidized under the simulated pan-frying conditions and the following results were obtained.
1) Amino acids such as phenylalanine, proline and tryptophan markedly inhibited the thermal oxidation of the oil in the presence of glucose. Lysine and histidine hydrochlorates, however, remarkably accelerated the thermal oxidation. Alginine and glycine did not show any effect.
2) The inhibitory effect of phenylalanine and proline against thermal oxidation of oil was apparently higher in the presence of glucose than in its absence, but this relation was reversed in the case of tryptophan.
3)When the oil was heated at 180°C for 5 min, tryptophan showed a remarkable inhibitofy effect, but was not effective at 200°C for 3 min.

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An inquiry on the taste perference was made to people ranging from 6 to 79 years of age in order to find the tendency of the preference toward sweet, sour, salty and bitter tastes. Respondents were classified according to sex and different age groups. The taste preference was investigated by using principal component analysis and cluster analysis. The results are as follows:
(1) The contribution rates of first, second and third principal component were 58.0%,30.4% and 6.4%, respectively. The first principal component could be interpreted as a total degree of the taste preference, the second as the difference of the taste preference, by ages, the third as the difference of the taste preference between males and females;
(2) The results of the cluster analysis indicate that sweet, sour, salty and bitter tastes may be classified into three groups;
(3) The old and middle-aged people had a tendency to prefer sweet and salty foods which are special products in Japan, the young people had a tendency to prefer sweet and sour foods and also for all age groups, the taste preference was little for bitter foods. The factors of age and sex were observed to influence the taste preference.

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The stability against oxidation, and aroma components of several sesame oils from seeds roasted at different temperatures were examined.
At a higher roasting temperature, the stability, sesamol content and brown color of sesame oil increased. Then, stability of sesame oil was observed to be dependent on sesamol and browning components derived by thermal reactions. Roasting of seeds above 200°C, gave remarkable antioxidative activity to the sesame oil.
By gas chromatographic analysis of head space volatiles from sesame oils, a sesame oil aroma and a smoky odor were stronger by roasting at a higher temperature. Roasting of sesame seeds at 180°C, brought a moderate sesame oil aroma on the sesame oil.
The above results showed the preferable roasting temperatures of sesame seeds to be 200°C for stability of sesame oil and 180°C for a sesame oil aroma.

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Differences between the taste characteristics of Korean and Japanese people were investigated by comparing the content and composition of free amino acids in Tsukemono, which is a traditional food in Japan, and Kimchi, which is eaten by Korean people.
The Kimuchi samples analyzed were produced in the home, in nunneries and by food manufacturers in Korea, and the Tsukemono used was produced by food, manufacturers in Japan.
High-performance liquid chromatography, using the orthophtaladehyde reaction system, was established to determine the free amino acids in Kimchi and Tsukemono. On the basis of glutamic acid content, Kimchi could be classified into the three types: (1) glutamic acid-rich kimchis (2) alaninrich kimchis (3) glutamic acid -deficient. On the other hand, Tsukemono contained a larger amonunt of glutamic acid.
From these results, it is presumed that Korean people prefer to eat Kimchi flavoured by seasonings such as “Shiokara”, wherease Japanese people especially prefer to eat Tsukemouo flavoured by glutamic acid.

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Buffering capacity, acidity and sugar content of ten commerical apple juice drinks and five kinds of laboratory-made apple juices were determined. Determinations of pH, Brix and color clifferrence of these juices were also carried out.
The buffering capacity of the samples was shown to he influenced by the concentration of the fresh apple juice added into the samples.
It was found that there were some difference among the acidity and pH of the samples. The reducing-sugar and sucrose contents of the samples ranged from 7.34% to 11.30% and from 0.28% to 2.78%, respectively.
The ratio (R/S) of reducing-sugar content to sucrose content was calculated.
The range of (R/S) for the laboratory-made juices and commercial juice drinks were 1.8 to 3.8and 2.6 to 40.4 respectively.
It seems that the values of the samples having higher authentic juice content were generaly smallar than the samples having lower authentic juice content.
There was no significant difference among the color difference of the samples.

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