RELATIONSHIPS BETWEEN PHYSICAL-CHEMICAL COMPOSITION OF RAW PEAS AND SENSORY ATTRIBUTES OF CANNED PEAS

Two pea cultivars (Citrina and Warindo) at four commercial sizes (superfine, very-fine, fine and middle) were selected for a study of their physical-chemical parameters of raw and sensory attributes after canning. To determine the relationships between the physical-chemical parameters and the sensory attributes, Principal Component Analysis (PCA) was applied. About 65% of the total variation in the physical-chemical parameters and sensory attributes was expressed by two PCA Factors. Mealiness was an important sensory attribute in determining the sensory quality of pea, and was related to tenderometric value, alcohol insoluble solids and starch content of raw seeds. General acceptance of canned peas by panelists was based on titratable acidity, green color and juiciness. Raw peas should be selected according to their dry matter, starch and titratable acidity, if they are to reach the consumer in an appetizing state when canned. This quality is mainly determined by general appearance, juiciness and flavor.     

油茶花提取物的美白功效评价

通过比较不同油茶副产品提取物的体外酪氨酸酶活性抑制作用,筛选出最佳抑制效果的油茶花提取物,并以曲酸作为阳性对照,采用体外培养的人A375黑素瘤细胞模型和斑马鱼胚胎模型探究其对体内外酪氨酸酶活性和黑色素合成的影响。结果表明,油茶花、油茶叶、油茶蒲和油茶粕提取物均表现出较好的酪氨酸酶活性抑制效果,其中油茶花效果最佳,其抑制IC50为0.49 mg/mL。与曲酸相比,油茶花提取物表现出极显著的胞内酪氨酸酶活性抑制作用和黑色素合成抑制作用(p<0.01),作用浓度为160 μg/mL时,胞内酪氨酸酶活性的抑制率达到34.30%,相对黑素含量减少了26.41%。当油茶花提取物暴露浓度为100 μg/mL时,其对斑马鱼体内酪氨酸酶抑制率达到32.47%,相对黑素含量降低至64.39%,作用效果与曲酸相当。油茶花提取物在体内外均表现出了较好的酪氨酸酶抑制效果,对细胞和斑马鱼黑色素生成具有显著抑制作用,且安全性高,是一种潜在的美白功能成分,在日用化妆品领域具有较高的应用前景。     

增容剂对尼龙6／乙烯~＝醋酸乙烯酯共聚物共混合金的亚微形态与力学性能的影响

采用两种含有羧基官能团的共聚物作为增容剂，通过反应挤出法制备了尼龙６／乙烯－醋酸乙烯酯共聚物（ＥＶＡ）共混合金；并对合金的力学性能和亚微形态进行了研究．结果表明，通过挤出过程中增容剂的羧基官能团与尼龙６反应，可提高尼龙６与ＥＶＡ的界面粘结性，从而使合金获得较高的缺口冲击强度，同时合金的断裂伸长率也显著提高ＳＥＭ研究显示，ＥＶＡ与尼龙６的相容性较差，基体中ＥＶＡ粒子直径约为１．５——２．０μｍ；而添加增容剂后，可以提高ＥＶＡ在基体中的分散性，并使分散相粒子的直径显著减小     

QUALITY ATTRIBUTES, PECTOLYTIC ENZYME ACTIVITIES AND PHYSIOLOGICAL CHANGES DURING POSTHARVEST RIPENING OF NECTARINE

The postharvest ripening at 20C and 90–95% RH for 10 days of ‘Armking’ nectarine grown in a greenhouse was investigated over two seasons. Firmness, titratable acidity, ascorbic acid, pH and maturity index were all adequate to stablish the rate of ripening. However, soluble solids content and reducing and non-reducing sugars showed no significant changes. It took about 10 days for very early ripening fruit (100 g weight and 82 N firmness) and 6 days for normal early ripening fruits (115 g weight and 46 N firmness), both harvested at preclimacteric stage, to become eating ripe (near 20 N). Total weight loss and decay after 10 days was approximately 11%. During ripening there was a temporal coincidence among higher rates of ethyleneproduction, higher pectinmethylesterase (PME) and polygalacturonase (PG) activities, lower firmness and acidity and higher maturity index. PME and PG activities increased during ripening, with a highly negative linear correlation between activities of the two enzymes and firmness. In very early ripening fruit, PME activity was more closely related to softening than PG, whereas in normal early ripeningfruit, PG activity was slightly more closely linked to the loss offirmness than PME.     

Biogenic Amines in Meat and Meat Products

It has been recognized for some time that biogenic amines occur in a wide range of foods, among them meat and meat products. Meat is an important component of the diet in developed countries. The presence of these amines in food is of interest for two reasons: firstly, for toxicological reasons, in the sense that high levels of dietary biogenic amines can be toxic for certain consumers, and secondly, for their role as possible quality indicators. Based on these two premises, the present article offers a new analysis on aspects of toxicology and on the use of biogenic amines as a quality control method, as well as on their presence in meat and meat products. The article focuses particularly on factors affecting the production of biogenic amines, with reference to various parameters relating to microorganisms, meat raw materials, and processing conditions. A better understanding of the factors determining their formation (i.e., microorganisms, raw materials used, and technological processes applied) and their effects could lead to ways of controlling their production, limiting their presence in the end product, and hence, rendering them less toxic.     

BREAKING UP IS HARD TO DO: EXPLAINING THE 2002 SAN FERNANDO VALLEY SECESSION VOTE

ABSTRACT: In November 2002 the voters of Los Angeles soundly rejected Proposition F which, if approved, would have authorized the secession of the San Fernando Valley in order to constitute a city independent of Los Angeles. This article attempts to delineate the interplay of social, economic, and political conditions related to support for secession by examining the results of a Los Angeles Times survey conducted one week prior to the vote. Because an exit poll was not taken following the vote, these data provide the most proximate evidence for the views of voters shortly before casting their ballots. The analysis of the data identifies distinctive social bases of support for secession in the San Fernando Valley that contrast with those outside the region. The results are interpreted in the context of Sonenshein's discussion of the role of coalition formation in urban politics.     

Use of Landsat data for automatic classification and area estimation of sugar-cane plantation in Sao Paulo state,Brazil

Sugar-cane (saccharum spp.) plantations in São Paulo State were classified automatically using an lmage-100 system and Landsat digital data. Ten segments of size 10 × 20 km were aerially photographed and used as training areas for automatic classification. The study area was covered by four Landsat paths, 235, 236, 237 and 238. The percentages of overall correct classification for these paths range from 79·56 per cent for path 238 to 95·59 per cent for path 237.