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Different Storage Times (different + storage_time)
Selected AbstractsCOLOR and CHLOROPHYLL CONTENT CHANGES of MINIMALLY PROCESSED KIWIFRUITJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2000MARÍA ASUNCIÓN LEUNDA A combined factors preservation technology involving blanching and vacuum solutes (sucrose, potassium sorbate, ascorbic and citric acids, zinc chloride) impregnation was proposed to minimize color changes in minimally processed kiwifruit slices during one month storage. Atmospheric impregnation was also studied in order to compare both impregnation techniques. A Box-Behnken design was adopted and second order polynomial models were computed for different storage times to relate some process variables (blanching time, zinc content, storage temperature) to a color function (Brown Index). As the storage time increased, the response surfaces for vacuum treated fruits were vertically displaced to greater Brown Index values while the response surface behavior for atmospheric impregnated fruits were less dependent on storage time. For vacuum treated fruits, combinations of blanching and addition of zinc chloride improved the color of the finished product at all storage temperatures assayed, but these treatments were detrimental for atmospheric impregnated fruits, increasing significantly the Brown Index values. After storage, total chlorophyll had been degraded between 70 and 90% depending on the pretreatments. There did not appear to be any consistent relation between the changes which occurred in the total chlorophyll content and color. [source] COMBINED EFFECT OF OSMOTIC PRESSURE AND SONICATION ON THE REDUCTION OF SALMONELLA SPP.JOURNAL OF FOOD SAFETY, Issue 4 2008IN CONCENTRATED ORANGE JUICE ABSTRACT The effect of osmotic pressure alone or combined with the application of sonication on the reduction of Salmonella spp. in concentrated orange juice was evaluated. Frozen concentrated orange juice (12.6 MPa, pH = 3.2), a neutral sugar solution (9.2 MPa, pH = 6.6) and an acid sugar solution (8.8 MPa, pH = 3.2) were inoculated with Salmonella spp. (6,7 log cfu/mL). Reductions were measured after different storage times with or without previous sonication treatment of 1 h (42 KHz,330W). No significant osmotic shock was observed. Reductions appeared to increase over storage time in high osmotic environments. Reductions were also significantly higher for sonicated samples when compared with nonsonicated samples. The highest reduction (7.21 log cfu/mL) was found for concentrated orange juice sonicated during 60 min and stored for 168 h. Combination of sonication and osmotic evaporation (osmosonication) represents a promising new technology that could be designed to athermally produce safe, concentrated fruit juices. PRACTICAL APPLICATIONS The results derived from this research indicate that combining sonication with osmotic pressure during storage of concentrated orange juice provides a way of achieving a >5-log reduction of Salmonella spp. A new promising technology that we call "osmosonication" could be developed, using sonication and osmotic evaporation combined, to athermally process fruit juices. Besides the nutritional and sensory benefits already known to be provided by athermal processes, final products would also be safe for the consumer. [source] CURRENT-STATUS SURVIVAL ANALYSIS METHODOLOGY APPLIED TO ESTIMATING SENSORY SHELF LIFE OF READY-TO-EAT LETTUCE (LACTUCA SATIVA)JOURNAL OF SENSORY STUDIES, Issue 2 2008MABEL ARANEDA ABSTRACT The objective of the present work was to develop a method for predicting sensory shelf life for situations in which each consumer evaluates only one sample corresponding to one storage time. This type of data is known as current-status data in survival analysis statistics. The methodology was applied to estimate the sensory shelf life of ready-to-eat lettuce (Lactuca sativa var. capitata cv."Alpha"). For each of six storage times, 50,52 consumers answered yes or no to whether they would normally consume the presented sample. The results were satisfactory, showing that the methodology can be applied when necessary. The Weibull model was found adequate to model the data. Estimated shelf lives ± 95% confidence intervals were 11.3 ± 1.2 days and 15.5 ± 0.9 days for a 25% and a 50% consumer rejection probability, respectively. PRACTICAL APPLICATIONS When considering shelf-life evaluations by consumers, the first idea is to have each consumer evaluate six or seven samples with different storage times in a single session. To do this, a reverse storage design is necessary, and in the case of a product such as lettuce, it would lead to different batches being confused with storage times. The methodology proposed in this article avoids this problem by having each consumer evaluate a single sample. Another issue with consumers tasting several samples in a single session is how representative this situation is of real consumption. The present methodology allows for a consumer to take home, e.g., a bottle of beer with an established storage time, and later collecting the information as to whether they found the beer acceptable or not. This is a situation much closer to real consumption. [source] SENSORY SHELF-LIFE ESTIMATION OF ALFAJOR BY SURVIVAL ANALYSISJOURNAL OF SENSORY STUDIES, Issue 6 2004ADRIANA GÁMBARO ABSTRACT Survival analysis methodology was used to estimate the shelf life of alfajor (a chocolate-coated individually wrapped cake) at 20 and 35C by using results obtained from consumers when asked if they would accept or reject samples with different storage times. Sensory acceptability (measured by consumers), off-flavor (measured by a trained panel) and moisture content were linearly related to time. These correlations were used to estimate values at the shelf-life times calculated for 25 and 50% rejection probability. Survival analysis provided the following shelf-life estimation: 74 days at 20C and 33 days at 35C for a 25% of rejection, 87 days at 20C and 39 days at 35C for a 50% of rejection. An alfajor stored at 20C having an acceptability value below 4.9 (1,9 hedonic scale) and off-flavor intensity above 5.3 (0,10 scale) would be rejected by 25% of the consumers. Chemical data were not good shelf-life predictors. [source] | ||||||||||