The influence of Cu and Sn on the hot ducti]ity at the strain rate of I O-'s~1 for steels with C contents from 0.002 to 0.1 5 masso/• was investigated, The hot ductility dropped at austenite +ferrite two phase region just be]ow A., namely, 800 to 900'C. The hot ductility deteriorated more at higher C content, and furthermore with the co-addition of Cu and/or Sn, It was considered that the deterioration at austenite+ferrite two phase region in the Cu, Sn bearing steel was caused by the combined effect of following factors: (1) the formation of proeutectoid ferrite along the austenite grain boundaries, (2) the segregation of Sn at the interface betweenproeutectoid ferrite and austenite or at the austenite grain boundaries, and (3) the increase in the difference of the deformation strength between austenite and proeutectoid ferrite.

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Aggregation and gelation of heated soybean proteins treated with stem bromelain were investigated by determination of sulfhydryl and hydrophobicity, by polyacrylamide gel electrophoresis and by scanning electron microscopy. The heat-induced, water-soluble soybean protein aggregates were initially unfolded by treatment with stem bromelain and released 7S and 4s proteins. The 2S protein was completely decomposed. The enzyme attacked the basic subunits of 11s globulin and converted them to low molecular weight fragments. Aggregation and gelation developed with icnrease of fragments. Noncovalent forces, possibly through hydrophobic interaction, played an important role in the aggregation process. Scanning electron microscopy revealed a fine network structure which suggested the combination of low molecular weight fragments.

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Chlorophylls were separated into a and b compounds by thin-layer chromatography and determined using a dual-wavelength chromatoscanner. A linear relationship existed in the range 0.1-I .O pg for chlorophyll a (chla) and 0.1-0.7 pg for chlorophyll b (chlb). The recoveries of chla and chlb when added to kiwi fruit were 79.4% and 99.5%, respectively. Total chla + chlb contents of four cultivars of kiwi fruit (Abbott, Bruno, Hayward and Monty) were 200&3000 pgl 1OOg at the beginning of growth, but decreased to about 1000 ug after four months. This decrease was mainly due to a decrease in chla. Total chlorophyll content decreased gradually during post-harvest ripening.