EFFECT OF STORAGE CONDITIONS ON THE SENSORY QUALITY OF GROUND ARABICA COFFEE

The objective of this study was to determine how long ground coffee beans could be stored at room and freezing temperatures before sensory changes could be detected, and to identify specific attribute changes associated with this storage. Ground beans were stored for 0 (fresh), 1, 2 and 3 weeks at room and freezing temperatures. Coffee was prepared from each of these treatments and difference testing was performed. Paired comparison tests were conducted on the fresh, 1‐ and 2‐week‐stored coffee grounds to examine the attributes of coffee aroma, flavor, bitterness and overall preference. At room temperature storage, results indicated significant (P < 0.05) differences in the coffee prepared from fresh versus the 2‐week‐stored ground beans. Coffee made from freshly ground beans had a stronger coffee aroma, less bitterness and was more preferred compared with the beans stored for 1 or 2 weeks (P < 0.05). At freezer storage, differences were detected between coffee prepared from coffee grounds stored for 1 or 2 weeks. Coffee prepared from grounds stored for 2 weeks had a stronger coffee aroma and was more bitter compared with the other storage times (P < 0.05).     

不同烹调方法对野生蔬菜品质的影响

研究了漂烫、微波和油炒三种烹调方法对野生蔬菜蒲公英、荠菜一些品质的影响。结果表明，与对照相比，漂烫均导致蒲公英和荠菜的氨基态氮、总酸性物质、维生素C、可溶性糖、亚硝酸盐和硝酸盐含量降低。微波使总酸性物质、可溶性糖、硝酸盐含量增加，氨基态氮、维生素C、亚硝酸盐含量降低。油炒则使总酸性物质、硝酸盐含量增加，氨基态氮、维生素C、可溶性糖、亚硝酸盐含量降低。因此，从对人体健康的角度考虑，在食用蒲公英和荠菜时最好先经过漂烫处理以降低硝酸盐含量。     

A STUDY OF THE EFFECT OF STORAGE AT 5°C ON THE MICROBIAL FLORA OF HEAT-TREATED MARKET CREAM

Changes in the microbial flora of heat-treated cream due to storage at 5°C for five days were studied. The relatively mixed flora of fresh cream at both 5°C and 30°C incubation temperatures appeared to vary according to source, with few psychotrophic organisms originally. After storage the flora became almost dominated by psychotrophic types with total numbers not less than 10⁶/ml, although the original numbers were very low indeed—in most samples less than 1500/ml.     

EFFECT OF PROCESSING AND STORAGE CONDITIONS ON THE MICROFLORA OF CLOSTRIDIUM PERFRINGENS-INOCULATED FRANKFURTERS

SUMMARY: The growth support potential of frankfurters for Clostridium perfringens was determined. Inoculated emulsions were stuffed into glass tubes and processed so that they reached an internal temperature of 68–69°C in 30–48 min. The tubes were sealed with agar plugs and rubber stoppers to simulate vacuum-packaging conditions. Total aerobic and anaerobic bacterial counts in uninoculated raw emulsion were 1 to 3 log cycles higher when petri dishes were incubated at 23°C as opposed to 37°C. The low-temperature-growing mesophiles and psychrotrophs were destroyed during processing. The 37°C counts were reduced 1 log cycle and the 23°C counts, 2 to 3 log cycles. Clostridium perfringens reproduced rapidly in frankfurters at 37 and 23°C, more slowly at 15 and 12°C, and not at all during 2 wk of storage at 10° or 4 wk at 0–5°C. Clostridium perfringens made up 2.5–10% of the total anaerobic count at 0 time but became the dominant organism during the storage at all temperatures permitting growth.     

超市销售条件下贮藏温度对洁净生菜保鲜效果的影响

本试验研究了模拟超市销售条件下生菜的贮藏与保鲜,超市生菜保鲜和贮藏夏天用的是(22±2)℃,冬天用的是(17±2)℃。结果表明,塑料薄膜包装的生菜低温(17±2)℃下贮藏,可以降低生菜的呼吸强度和蒸腾作用,减少还原糖、抗坏血酸、和叶绿素含量的损失,从而有利于生菜品质的保持和货架期的延长。     

EFFECT OF STORAGE AND PROCESSING CONDITIONS ON SORGHUM KERNEL STRENGTH

Compressive strength of sorghum kernels was measured to determine the effect of storage conditions on processing for animal feed. Ensiling grain affected a larger decrease in kernel compressive strength than did storage at a high moisture level. Results similar to the above were noted for tests conducted on kernels obtained from animal feces. Microscopic examination of kernels from each treatment revealed greater removal of kernel structure for those of lower compressive strength.     

EFFECT OF STORAGE PERIOD AND EXPOSURE CONDITIONS ON THE QUALITY OF BOSANA EXTRA-VIRGIN OLIVE OIL

Changes in quality parameters, antioxidant compounds, oxidative stability and antioxidant activity during 18 months of storage of a monovarietal extra‐virgin olive oil from Bosana cultivar , and exposed to light and dark, were studied. Analysis of data showed that all the parameters underwent significant changes during storage: free acidity, peroxide and ultraviolet (UV) spectrophotometric indexes remained below the limits reported in the EEC Regulations 2568/91 and 1989/03 , and these are: ≤0.8% for acidity, ≤20 meq O₂/kg for peroxide and ≤2.50 and ≤0.22 for K232 and K270, respectively. Phenol andα‐tocopherol content decreased during storage (42.0 and 29.6%, respectively) while chlorophylls and carotenoids underwent a decrease until 8 months of storage (49% and 30%, respectively); after that, the values remained constant. Oxidative stability and antioxidant activity had not changed dramatically during 18 months. Phenols were significantly correlated to the antioxidant activity of the oil, while oxidative stability measured by Rancimat did not show any correlation with carotenoids, chlorophylls, phenols andα‐tocopherol. Regarding exposure conditions, storage in the dark was better in retaining the quality of the oil, as expected.     

温度对豇豆采后保鲜效果影响的研究

为探明贮藏过程中温度对豇豆保鲜效果的影响,研究了温度与豇豆在贮藏过程中的外观变化及其生理指标变化的关系.结果表明:豇豆豆荚在室温(30℃～35℃)下的贮藏寿命为4d.低温(10℃)贮藏能够降低豇豆豆荚的水分散失,减缓豆荚中VC和叶绿素含量的下降,抑制其呼吸速率,维持豆荚细胞膜的完整性,使豇豆的贮藏寿命延长到12 d.     

EFFECT OF STORAGE CONDITIONS ON THE CHEMICAL, PHYSICAL AND SENSORY CHARACTERISTICS OF STANLEY PLUM PASTES

Stanley plums were processed into purees and then pastes by heat concentration to 25 and 30⁰ Brix. The Brix of these two pastes was increased to 40 and 45⁰, respectively, by sugar addition. Pastes were stored at 4 and 22 ± 2C in the dark for up to 24 weeks. Physical-chemical characteristics and microbiological quality were determined at 4 week intervals. Sensory evaluation was conducted at 0 and 24 weeks. Total solids, water activity, rheological properties and microbiological quality were stable during storage. Total acid, total anthocyanins, total pectin and Hunter ‘L’ and ‘a’ values decreased significantly during storage (P < 0.01). The degradation rate of total anthocyanins was much higher for pastes stored at 22C than those at 4C. Hue angle and Hunter ‘b’ values increased during storage. Sensory evaluation indicated that pastes were still acceptable after 24 weeks of storage.     

THE EFFECT OF THE COLLOIDAL STATE OF THE EMULSION ON ICE CREAM STRUCTURE

Ice creams with different ‘stand-up’ characteristics have been prepared using the same basic mix but without emulsifiers. This has been achieved by allowing the gelatin stabiliser to compete for the oil-water interfaces in the emulsion yielding mixes of varying emulsion stability. The emulsion stability varies according to the ratio of gelatin to milk protein present at the homogenisation stage and shows a minimum which corresponds to ice creams with maximum stand-up. The data provides an independent check of the theory of Kloser and Kenney in mixes not containing lipid emulsifiers.     

不同储期酸奶对小鼠免疫功能和游泳耐力的影响

探讨不同储期酸奶对小鼠免疫功能和游泳耐力的影响.以原味酸牛奶为受试物,试验分5组,每组20只,各组分别灌喂0.9%的生理盐水和储存0、3、6、9d的酸奶,1 mL/只·d,连续灌喂28d;对小鼠进行游泳耐力、腹腔巨噬细胞吞噬鸡红细胞、免疫器官指数、血清溶血素含量、血细胞计数的测定.酸奶可明显提高小鼠游泳耐力、巨噬细胞的吞噬率、脏器指数、血清溶血素的含量,增加血液中的白细胞、红细胞和血红蛋白的量;其中储存3 d的效果最好,其次是0d,6d和9d次之.酸奶可以提高机体的免疫功能,尤其是储存了3d的酸奶.     

EFFECT OF PHORONE ON ACCUMULATION AND FATTY ACID COMPOSITION OF SURFACE LIPID OF APPLE DURING STORAGE

Phorone added to apples after harvest stimulated the rate of accumulation of surface lipid and decreased the rate of water loss when fruit were stored at 0°C but had the opposite effect in fruit stored at 5, 10 or 20°C where lipid accumulation was inhibited and water loss enhanced. The fatty acid composition of surface lipid from phorone-treated fruit showed a higher proportion of linoleic acid at all temperatures. For oleic and linolenic acids, a differential effect of storage temperature occurred with phorone-treated fruit at 0°C developing a lower proportion of oleic acid and a higher proportion of linolenic acid compared to control fruit whereas at 5° and 20°C the reverse occurred.     

EFFECT OF TIME AND STORAGE CONDITIONS ON MAJOR VOLATILE COMPOUNDS OF ZALEMA WHITE WINE

ABSTRACT

Changes in quality attributes during bottled storage of white wine were studied. Different storage conditions, temperature, bottle position and exposure to light were studied over 1 year and their effects on major volatile compounds were evaluated. Ethyl lactate and diethyl succinate contents increased after 12 months of storage, whereas isoamyl acetate decreased over this period. The analysis of variance revealed that the temperature had a statistically significant effect on most volatile compounds studied. Multivariate statistical techniques (specifically principal component analysis and linear discriminant analysis) confirmed that temperature is the most important factor, so the samples were distributed into two groups according to storage temperature. A rough differentiation among wines according to the length of storage was also obtained using linear discriminant analysis.

PRACTICAL APPLICATIONS

Aroma is one of the main factors contributing to the quality of wines and their acceptance by consumers. However during bottle storage, young white wines lose their fresh and fruity flavor and suffer a browning process. Among other factors, the time it takes a wine to spoil depends on the wine composition and on storage conditions. Knowledge of the bottle storage stability of Zalema young white wines could allows us to predict their shelf life and establish the best commercial storage conditions to retain their organoleptic characteristics for longer periods.