Anthocyanin Pigments: Comparison of Extract Stability

Stabilities of anthocyanins from Concord grapes, red cabbage, tradescantia and ajuga were studied. RP-HPLC analysis was used to characterize individual anthocyanins and spectrophotometric analysis for all pigments. Anthocyanins from tradescantia were much more stable than the other extracts. Such increased stability was attributed to its intrinsic nature.     

干酪及其加工和质量控制新技术

研讨了国外奶酪及其发展、奶酪的品种、分类和质量控制方法，进一步介绍了近年研发出的新型奶酪的特点和加工方法。同时还研讨了乳清及其生物活性物的最新研究进展，以利于充分利用乳清资源和减少排除的乳清对环境的污染。另外，还介绍了奶酪加工新技术和凝乳酶的新型代用酶的种类、特性。     

MICROFLORA CHANGES IN MISTED AND NONMISTED BROCCOLI AT REFRIGERATED STORAGE TEMPERATURES

Plate counts of three groups of microorganisms [aerobic plate count (APC), coliforms (C), and yeast and mold (Y/M)] were determined in misted (M), nonmisted in the same cold room (SNM), and nonmisted in a different cold room (DNM) broccoli stored at 4 ± 1C for five days. Relative humidity of the cold rooms, moisture content of the broccoli, and microbial quality of the misting water were also determined. Two-way ANOVA indicated significant differences (p ≤ 0.05) between M, SNM and DNM treatments. Misting was found to minimize the increase in plate counts of the three microorganism groups monitored. Higher relative humidity in the misted samples compared with the nonmisted samples, the washing effect of the misting water and possible residual chlorine effects due to the use of chlorinated tap water may explain the reduced viable counts observed in the misted samples.     

Isolation and Heat Stability of Trypsin Inhibitors in Amaranth (Amaranthus hypochondriacus)

Trypsin inhibitors were isolated from seeds of Amaranthus hypochondriacus by extraction at pH 7.5, heat treatment at 70°C for 15 min and affinity chromatography with trypsin-Sepharose 4B. Inhibitors of trypsin and chymotrypsin were identified in polyacrylamide gels following electrophoresis using a stain procedure that employed the chromogenic substrate acetyl-D, L-phenylalanine-2-napthyl ester. Three of the thirteen trypsin inhibitors identified in the electrophoresis gels, also had antichymotryptic activity. The inhibitor preparation was very thermostable retaining 20% of its original activity after 7 hr at 100°C.