排序方式: 共有19条查询结果,搜索用时 15 毫秒
1.
DAVID SEPÜLVEDA GUADALUPE OLIVAS JOSE-JUAN RODRIGUEZ HEIDI WARNER STEPHANIE CLARK GUSTAVO BARBOSA-CÁNOVAS 《Journal of Food Processing and Preservation》2003,27(3):227-242
Changes in specific physico-chemical and sensory attributes as well as acceptability of beefsteak and beef stew Meal-Ready-to-Eat (MRE) components packed under different headspace levels (10, 20, 30 and 40 cm3 ) and stored at selected temperatures of 4, 27 and 38C (40, 80 and 100F) were evaluated over a six month period. No significant changes in microbial counts, pH, residual oxygen, color, hardness and oxidation occurred in retort-packed beefsteak or beef stew. Unlike beefsteak, beef stew received acceptable scores by consumers during all six months of analysis. Consumers' lack of familiarity with beefsteak may have negatively influenced product acceptability. Beefsteak and beef stew acceptability and specific attributes, particularly moistness and firmness, were detrimentally affected by high storage temperatures. Headspace may be increased to 40 cm3 without significant detrimental effects on product quality and acceptability of beefsteak or beef stew. 相似文献
2.
3.
STABILIZATION OF CARROT JUICE BY DILUTE ACID TREATMENT 总被引:1,自引:0,他引:1
THOMAS S. STEPHENS GUADALUPE SALDANA HAROLD E. BROWN FRANCIS P. GRIFFITHS 《Journal of food science》1971,36(1):36-38
SUMMARY– A problem arises if juice extracted from raw carrots is heated to about 180° before or during conventional canning practices. An unsightly, unappetizing coagulum forms and the color of the juice precipitates with the coagulum. The coagulum is not as evident if the carrots are heated 5 min in water prior to juice extraction, but the juice loses some of its bright-orange color. The canned juice extracted from carrots heated 5 min in a .05 N acetic acid solution does not coagulate and the amount of juice which can be extracted from the carrots is 3.3% greater than that from carrots heated 5 min in water. The centrifuged juice from acid-treated carrots had a brighter orange color than juice from the water-treated carrots. The color notation was Rd, 23.7, a, 30.4 and b, 34.8 for juice from acid-treated carrots compared with a notation of Rd, 19.2, a, 24.4 and b, 31.4 for the juice from water-treated carrots. The canned juice extracted from raw carrots had less pectic substances and starch and about the same amount of protein as the canned juice from the carrots heated in water or .05 N acetic acid, but the canned juice from raw carrots coagulated. The juice from carrots heated in acid does not form a coagulum and maintains its orange color, probably because of the action of the heat and acid on the protoplasmic liquid of the cell before or immediately after the cell is ruptured. 相似文献
4.
5.
JORGE F. TORO-VAZQUEZ GUADALUPE MENDEZ-MONTEALVO MIRIAM A. CHARÓ-ALONSO 《Journal of Food Lipids》2000,7(3):151-162
In a sesame oil miscella (40% and 60%) system the adsorption efficiency for free fatty acids (QFFA .) and carotenoids (Qc ) provided by pine wood carbon (also known as vegetable carbon), two commercial synthetic silica adsorbents, and rice hull ash were compared at different adsorbent dosages (1.0, 2.5 and 5.0%).
At all the adsorbent dosages investigated the pine wood carbon achieved a higher QFFA than synthetic silicas and rice hull (P < 0.05). This effect was more evident as the carbon concentration decreased (P < 0.05). However, in the case of carotenoids none of the adsorbents exhibited a significant advantage in Qc (P < 0.50) at any of the adsorbents dosages utilized. Rice hull ash had the highest oil retention, while silicas exhibited an oil retention profile with lower values than that obtained with pine wood carbon (P < 0.10). The results suggest that pine wood carbon might have the same capability as silicas when used with sequential addition of clay in sesame oil miscella refining, with the advantage of higher adsorption efficiency than silicas for free fatty acid adsorption. 相似文献
At all the adsorbent dosages investigated the pine wood carbon achieved a higher Q
6.
GUADALUPE PRÉSTAMO 《Journal of food science》1989,54(3):760-760
Peroxidase from kiwifruit (Actinidia chinensis) was extracted, precipitated with ammonium sulfate, and purified by DEAE-cellulose chromatography. Only one band with peroxidase activity with an estimated molecular weight of 40,00–42,000 daltons was found by sodium do-decyl sulfate-polyacrylamide gel electrophoresis. 相似文献
7.
ERUALDO ROMERO GONZLEZ RAUL P. LEJANO GUADALUPE VIDALES ROSS F. CONNER YUKI KIDOKORO BAHRAM FAZELI ROBERT CABRALES 《Journal of Urban Affairs》2007,29(1):77-100
ABSTRACT: The community‐based approach to health research and intervention is a model of inquiry rooted in Freire's participatory action research (PAR). We need to show, in concept and practice, what it is about PAR that may be well suited for the types of health issues we encounter in inner‐city environments. What type of learning results, how does this respond to particular health issues in the urban context, and what are the particular challenges faced in translating Freire's model into today's urban setting? To investigate these questions, we describe a recent PAR project in Southeast Los Angeles, California—an area known to some as “Asthmatown.” One salient finding of the research is that PAR allows the integration of complex and multiple forms of knowledge, and this is a necessary response to the complex and multiplex nature of cumulative impacts. There are challenges to translating the model to the urban setting, however, such as the difficulties of participation in today's urban milieu. The research leads to some lessons for practitioners, such as the need to build “constant” elements into PAR projects. Lastly, we reflect on implications of this model for institutional reform. 相似文献
8.
GUADALUPE LUNA-SOLANO MARCO A. SALGADO-CERVANTES MIGUEL A. GARCIA-ALVARADO GUADALUPE RODRIGUEZ-JIMENES 《Journal of food process engineering》2000,23(6):453-462
Active dry brewer's yeast was prepared by spray drying (Tout 50 and 60C). Addition of processing aids to the yeast cream was necessary in order to dry at these temperatures. Corn starch (grits) and maltodextrins (DE‐6) two levels of additions (10 and 20%) were used as processing aids. Statistical analyses proved that processing aids concentration, air outlet temperature and rotor speed had significant effects on yeast viability. Dried samples could be preserved at least 4 months stored at 5 and 25C with a loss of 1 and 2 log cycles of viable cells, respectively. 相似文献
9.
IRMA BERNAL-LUGO GUADALUPE PRADO CARMEN PARRA ERNESTO MORENO JORGE RAMÍREZ OSCAR VELAZCO 《Journal of Food Biochemistry》1990,14(4):253-261
Two bean cultivars were stored over a 33-day period (75% RH and 41°C). After this period, cooked hardness, levels of phytate, phytase activity and integrity of protein bodies were monitored. The Michigan cultivar, which was the most susceptible to hardening, showed higher initial content of phytate which decreased by 20.7% after 30 days of storage. In contrast, Ojo de cabra, the cultivar less susceptible to hardening, presented lower initial content of phytate and a marked drop of 66.1% in its level during the same period of time. The phytase activity and the autolytic protein body destruction were higher in the last one than those in the former one. These results suggest that the contents of phytate or its rate of hydrolysis are not the major contributor to the seed susceptibility to storage induced hardening of different bean varieties. 相似文献
10.
HAROLD E. BROWN FILMORE I. MEREDITH GUADALUPE SALDAMA THOMAS S. STEPHENS 《Journal of food science》1970,35(4):485-488
SUMMARY— A process of peeling tomatoes using low temperature-short time freezing was perfected. Liquid nitrogen (BP-196°C was used as the refrigerant for freezing the skin and only a thin layer of cells just beneath the skin. The fruit was immediately thawed, after which the skin was quickly and easily removed from the fruit. Liquid nitrogen-peeled samples were evaluated for loss of peel and trim, as well as lycopene and carotene in the peeling process and these losses compared with samples peeled in boiling water. The losses in peel and trim were reduced by approximately 50%, and significantly less lycopene was lost by nitrogen peeling. The peel and trim of fall tomatoes had a greater amount of lycopene and carotene than spring tomatoes. The nitrogen-peeled samples were canned without additives, with sodium chloride and with calcium chloride added and compared with samples peeled with boiling water. There was a decrease in the percentage of broken fruit in the canned tomatoes peeled by liquid nitrogen. Titratable acidity and °Brix were higher and pH was lower in these samples. Color of the homogenized canned product was not statistically different; however, the nitrogen-peeled tomatoes had a better visual color. The calcium chloride added-nitrogen-peeled samples possessed a higher degree of firmness than the comparably treated boiling-water-peeled samples, indicating that the nitrogen-peeled tomatoes utilized the added calcium to a greater extent in firming. 相似文献