Texture of Jet Cooked, High Amylose Corn Starch-Sucrose Gels

Not many studies have examined changes in microbial transglutaminase (MTG) yoghurts during storage. In this work, yoghurts manufactured with skimmed milk and treated with MTG were evaluated in refrigerated storage for 35 days. Instrumental measurements showed that firmness, consistency and pH values in MTG yoghurt experienced a significant increase with the storage time. However, sensory measurements showed that MTG yoghurts were not affected significantly by storage time. Acid taste scores only increased significantly with storage time in the control samples. Microbial transglutaminase treatment showed a positive effect on textural properties and allowed syneresis to be prevented completely during storage.

Effects of temperature, storage time and their combination on germination of aspen (Populus tomentosa) seeds were investigated. Aspen seeds were germinated at 5 to 30°C at 5°C intervals after storage for a period of time under 28°C and 75% relative humidity. The effect of temperature on aspen seed germination could not be effectively described by the thermal time (TT) model, which underestimated the germination rate at 5°C and poorly predicted the time courses of germination at 10, 20, 25 and 30°C. A modified TT model (MTT) which assumed a two-phased linear relationship between germination rate and temperature was more accurate in predicting the germination rate and percentage and had a higher likelihood of being correct than the TT model. The maximum lifetime threshold (MLT) model accurately described the effect of storage time on seed germination across all the germination temperatures. An aging thermal time (ATT) model combining both the TT and MLT models was developed to describe the effect of both temperature and storage time on seed germination. When the ATT model was applied to germination data across all the temperatures and storage times, it produced a relatively poor fit. Adjusting the ATT model to separately fit germination data at low and high temperatures in the suboptimal range increased the models accuracy for predicting seed germination. Both the MLT and ATT models indicate that germination of aspen seeds have distinct physiological responses to temperature within a suboptimal range.

Red lentil (Lens culinaris Medikus), an important pulse crop produced in Western Canada, is mainly consumed as split or whole cotyledon (“football”) after the seed coat has been removed through dehulling. However, related information on the effects of storage time, postharvest treatments and storage temperature on the dehulling efficiency and cooking quality of red lentils at different moisture contents are not readily available for processors, marketers, breeders, as well as growers. The objective of this study is therefore to investigate the effect of storage temperature, postharvest treatments and storage time on the dehulling efficiency and cooking quality of red lentil. While a laboratory Satake dehuller was used to evaluate the dehulling characteristics of red lentil, an automated Mattson cooker was used to determine the cooking quality. Red lentil of ‘Robin’ variety for 2007 harvest with moisture contents of 10.07%, 11.31% and 13.27% w.b., as well as ‘Robin’ samples for 2008 harvest of moisture contents 10.13%, 11.52% and 13.37% were kept in storage at two temperatures of 5oC and 25oC. In addition, samples with the moisture contents of 10.07%, 10.13%, 13.27% and 13.37% were subjected to three freeze-thaw cycles and stored at 5oC only. Similar treatments were given to lentil samples of ‘Impact’ variety with moisture contents of 10.21%, 11.56%, and 13.14% w.b. for 2007 harvest and 10.33%, 11.48% and 13.54% for 2008 harvest. In addition, lentil sample of ‘Impact’ and ‘Robin’ varieties at 13.14% and 13.27% (w.b.) moisture contents for 2007 harvest as well as 13.54% and 13.37% moisture contents for 2008 harvest respectively were further reconditioned to a moisture content of 18% (w.b.). As part of the postharvest treatment, these samples were dried at near ambient temperature and at 80°C under forced convention (simulating extreme drying conditions) to two final moisture contents of 10% and 13%. These samples were further stored at 5°C and 25°C. Dehulling efficiency and cooking quality were determined after 1 and 6 month storage. Also, lentil sample (2007 harvest) of ‘Impact’ variety at 10.21% and 13.14% as well as ‘Robin’ variety at 10.07% and 13.27% moisture contents were subjected to 5 cycles of drying and rewetting in the range of ±2% from its nominal moisture and tested for quality (dehulling efficiency and cooking quality) after 1 and 2 months storage at 5°C. This same postharvest treatment was given to lentil sample (2008 harvest) of ‘Impact’ variety at 10.33% and 13.54% moisture contents as well as ‘Robin’ variety at 10.13% and 13.37% moisture contents. Tests on dehulling efficiency and cooking quality were conducted at specific time intervals. Generally, there was a decrease in the dehulling efficiency values of ‘Robin’ and ‘Impact’ lentil samples with storage time up to 12 months for both harvest years (2007 and 2008). Among the postharvest treatments considered in this study, the drying and rewetting of lentil samples (‘Robin’ and ‘Impact’) had the most significant impact on dehulling efficiency. For other postharvest treatments, the trends were not consistent. In some cases dehulling efficiency increased for samples dried at 80°C, but observations like this were not consistent for other variety. Generally, storage time did not affect the cooking time values of ‘Robin’ and ‘Impact’ lentil samples. This is true for samples stored at 5°C, 25°C and 5°C subject to freeze thaw cycles, and also those subjected to other postharvest treatments at different moisture contents. Drying and rewetting of ‘Robin’ and ‘Impact’ lentils significantly increased the cooking time of these samples.

Effect of storage time on the characteristics of corn and efficiency of its utilization in broiler chickens.

Heart disease is a leading cause of death in the United States. Omega-3 (n-3) fatty acids (FA) positively affect heart health while high levels of cholesterol are an indication of poor heart health. Nutritionally-enhanced low-cholesterol egg sticks fortified with n-3 FA were developed; quality indicators were measured and sensory evaluations were conducted. Store-bought eggs were separated and egg whites were mixed with oil, spray dried egg whites, annatto (color) and salt. The oil sources included: algae, menhaden, flaxseed, and canola oils. Experimental egg batters and mixed whole egg (control) were cooked in the shape of a cheese stick, vacuum packed, and stored at 4C. Quality indicators (color (L*, a*, b*), texture, pH and lipid oxidation) of egg sticks were measured over a storage period of 14-d. There were no changes in color over time (P>0.05); however, whole egg was significantly less red and yellow compared to experimental eggs (P<0.05). Significant differences in texture properties were observed (P0.05). A difference in pH between egg types was seen (P0.05). No trend in lipid oxidation was seen over storage time (P>0.05). Egg sticks were evaluated by a consumer panel of 56 participants for color, odor, flavor, texture between fingers, mouth feel and overall liking with a 9-point scale (1=dislike extremely; 9=like extremely). Panelists also ranked samples from most to least liked. The texture between fingers of the whole egg was significantly more liked than the experimental eggs containing DHAS and canola oils (P<0.05). Odor scores were significantly greater (P<0.05) in whole egg compared to the experimental egg containing flaxseed oil. No significant preference was observed in mouthfeel or flavor. All samples were well-liked, with a combined average score of 5.9. Ranking results support this conclusion with no significant differences in preference (P>0.05). The results indicate that the experimental eggs are accepted by consumers on the same level as mixed whole eggs and may have potential as a marketable product.;Key words: Omega-3, Egg, TBARS, texture profile analysis, functional food, egg composition, sensory evaluation.

Effects of temperatures and storage time on resting populations of Escherichia coli O157:H7 and Pseudomonas fluorescens in vitro

The effects of storage time and temperature and anticoagulant on laboratory measurements of canine blood progesterone concentrations

Storage of cellulose solution can be practically ineluctable before it is manufactured into various regenerated products (e.g., fibers, films), especially in the case of industrial production. Therefore, it is necessary to evaluate the effect of storage time and temperature on the dissolved state of cellulose in the interested TBAH-based solvents (including TBAH/H2O, TBAH/H2O/DMSO, TBAH/H2O/Urea), as well as on the mechanical property of the relevant regenerated products (films were prepared in this work for the evaluation). The dissolved state of cellulose in these solvents along with storage has been analyzed with the polarized light microscope photographs and Stormer viscosity. Focus on the interested TBAH/H2O/DMSO solvent, the effect of storage time and temperature on the solution viscosity, and degree of polymerization of cellulose have been discussed. Critical storage time for different storing temperature has been determined, after where significant cellulose degradation happens. A series of regenerated cellulose films with storage time ranging from 0 to 200 h have been prepared. The optimal storage time and strengthening mechanism for cellulose films regenerated from the solution of cellulose/TBAH/H2O/DMSO have been discussed. This work can provide reference about storage time and temperature of cellulose/TBAH/H2O/DMSO, especially for the production of pilot-scale, etc.

Summary With advantages of long shelf life, high convenience and reliable safety, frozen steamed bread (FSB) is suitable for industrial production. Storage conditions are critical factors influencing the final quality of FSB. In this study, the effects of storage time, storage temperature and freeze–thaw cycles on the quality of FSB were evaluated. Results showed that the water loss of FSB and the retrogradation of the starch occurred during the storage process. The final gelatinization degree of FSB decreased from 88.69% to 86.37%, whereas the crystallinity gradually increased from 16.78% to 18.47%. As storage temperature of −18 °C could not kill microorganisms, metabolites of microorganisms caused a decrease in the pH value from 5.41 to 5.10 after the 90 d of frozen storage at −18 °C. Re‐steaming properties results showed that the specific volume and whiteness of re‐steamed FSB decreased significantly with the storage time, as well as the textural properties and sensory evaluation score. Furthermore, freeze–thaw cycles were found to accelerate the quality deterioration of the FSB, and compared with the temperature of −18 °C, frozen temperature of −30 °C alleviated the quality deterioration of FSB.

Bread is a staple food widely consumed worldwide and therefore represents an excellent vehicle for increasing nutrient intake. In this context, the incorporation of chickpea flour into bread offers promising nutritional benefits; however, its impact on bread technological quality remains underexplored. This study investigated staling phenomena in composite breads produced by substituting wheat flour with chickpea flour at 0%, 10%, 20%, and 30%. Moisture content, texture, and viscoelastic properties were monitored over 7 days of storage. Dynamic mechanical analysis (DMA), including frequency sweep and temperature scan tests, was employed as a less commonly used tool to evaluate mechanical changes associated with staling and formulation. Multivariate analyses were used to assess the effects of chickpea flour and storage time on bread properties. Hardness was found to be correlated with viscoelastic parameters obtained by the DMA frequency sweep test. The DMA temperature scan was able to measure the mechanical changes associated with frozen water transition, showing a significant decrease in ice melting temperature related to chickpea flour inclusion (~3°C) and storage time (~2.5°C). Among the different parameters used to describe thermal transitions (storage and loss moduli drops and tanδ peak), it was identified which of these was most effective in discriminating the samples as an effect of both chickpea flour and storage time. Overall, these results support the potential of DMA as a complementary analytical approach for assessing staling and mechanical changes evolution in chickpea‐enriched bread, providing new insights into formulation‐induced structural changes during storage.

ABSTRACTThe effects of drying conditions, final moisture content, and degree of milling on the texture of cooked rice varieties, as measured by texture profile analysis, were investigated. Instrumentally measured textural properties were not significantly (α = 0.05) affected by drying conditions, with the exception of cohesiveness. Cohesiveness was lower in rice dried at lower temperatures (18°C or ambient) than in that dried at the higher commercial temperatures. Final moisture content and degree of milling significantly (α = 0.05) affected textural property values for adhesiveness, cohesiveness, hardness, and springiness; their effects were interdependent. The effects of deep milling were more pronounced in the rice dried to 15% moisture than that dried to 12%. In general, textural property values for hardness were higher and those for cohesiveness, adhesiveness, and springiness were lower in regular‐milled rice dried to 15% moisture than in that dried to 12%. In contrast, hardness values were lower and cohesiveness, adhesiveness, and springiness values were higher in deep‐milled rice dried to 15% moisture than in that dried to 12% moisture. Deep milling resulted in rice with lower hardness values and higher cohesiveness, adhesiveness, and springiness values.

Texture profile analysis (TPA) was conducted on seventy balady bread samples collected from different five Egyptian governorates (i.e. Cairo, Giza, Beheira, Sharkia and Beni Suef) with the aim of developing a new and fast method to assess the staling of the Egyptian flat balady bread as a function of different TPA parameters. Results obtained from the TPA were compared against the classical Alkaline Water Retention Capacity (AWRC) method of bread staling determination over a storage period of three days. Hardness, adhesiveness, resilience and chewiness were found to increase as the storage period of bread samples increased, while cohesiveness decreased with the storage. The obtained results of TPA showed that among different TPA parameters, hardness, adhesiveness, cohesiveness and chewiness were highly correlated with the staling rate (SR) during a three days storage period with values of correlation coefficients ranging from 0.821 to 0.973, while other TPA parameters (i.e. gumminess, resilience and springiness) were weakly correlated with the staling rate. Moreover, moisture content was linearly decreased as the storage of bread increased from 36.78 at the zero time to 33.19% at the third day. Derived mathematical models to calculate the AWRC and SR were significant and of the linear type with moisture content, time (day), hardness, cohesiveness, adhesiveness and chewiness as independent variables, with reasonable adjusted R2 ( 0.55 and 0.41), and adequate precision values (31.57 and 18.68) for AWRC and SR, respectively . Validation of the new method, as assessed by t-test, showed that the differences between AWRC and SR values obtained by our method were not significantly different (P<0.05) from those of their counterparts obtained by the classical AWRC method at the different storage times of bread. Our new method can be used as an alternative to the classical AWRC method with reliable, fast and accurate calculated values of both AWRC and SR.

Texture evaluation of block-type processed cheese as a function of chemical composition and in relation to its apparent viscosity

Microstructure and physicochemical properties: Effect of pre-chilling and storage time on the quality of Channel catfish during frozen storage

The objective of our study is to evaluate the effect of storage temperature and time to analysis on arterial blood gas parameters in order to extend the CLSI recommendations. Stability of 12 parameters (pH, pCO₂, pO₂, Na+, K+, Ca2+, glucose, lactate, hemoglobin, oxyhemoglobin, carboxyhemoglobin, methemoglobin) measured by GEM PREMIER™ 5000 blood gas analyzer was studied at room temperature and at +4 °C (52 patients). The storage times were 30, 45, 60, 90 and 120 min. Stability was evaluated on the difference from baseline, the difference from the analyte-specific measurement uncertainty applied to the baseline value, and the impact of the variation on the clinical interpretation. At room temperature, all parameters except the lactate remained stable for at least 60 min. A statistically significant difference was observed for pH at T45 and T60 and for pCO2 at T60 without modification of clinical interpretation. For lactate, clinical interpretation was modified from T45 and values were outside the range of acceptability defined by the measurement uncertainty. All parameters except pO2 remained stable for at least 120 min at +4 °C. A one-hour transport at room temperature is compatible with the performance of all the analyses studied except lactate. If the delay exceeds 30 min, the sample should be placed at +4 °C for lactate measurement. If the samples are stored in ice, it is important to note that the pO2 cannot be interpreted.