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Heat Pretreatment (heat + pretreatment)
Selected AbstractsEffects of Heat Pretreatment on Lipid and Pigments of Freeze-Dried SpinachJOURNAL OF FOOD SCIENCE, Issue 8 2001E. Cho ABSTRACT: Heat pretreatment resulted in decreases in drying yield and glycolipids (GL) and an increase in neutral lipids (NL). Triacylglycerol and free sterols in NL and sterylglycosides and monogalactosyldiglycerides in GL were more stable during heat pretreatment. Phosphatidylglycerol, phosphatidylethanolamine, and phosphatidic acid among phospholipid subclasses were more susceptible. There was no large difference in fatty-acid composition of spinach lipids by heat pretreatment. However, a significant decrease in linolenic acid and increases in oleic and hexadecenoic acids were observed in NL. Contents of chlorophyll, lutein, and ,-carotene in spinach decreased by heat pretreatment, with the least decrease in lutein. [source] Heat acclimation and cross-tolerance against anoxia in ArabidopsisPLANT CELL & ENVIRONMENT, Issue 7 2008VALERIA BANTI ABSTRACT Arabidopsis seedlings are highly sensitive to low oxygen and they die rapidly when exposed to anoxia. Tolerance to anoxia depends on the ability to efficiently use carbohydrates through the fermentative pathway, as highlighted by the lower tolerance displayed by a mutant devoid of alcohol dehydrogenase. Other mechanisms of tolerance are also possible and may include a role for heat-induced genes. In fact, heat shock proteins (HSPs) are induced by anoxia. This suggests that there may be a cross-adaptation mechanism between heat and anoxic stress, and in this work, we studied the acclimation of Arabidopsis seedlings both to low oxygen and heat. The results show that seedlings subjected to hypoxia or heat pretreatment survive anoxia much better. Interestingly, we also observed an increased anoxia tolerance in heat-treated alcohol dehydrogenase (adh) mutant plants. On the other hand, anoxic pretreatment does not confer tolerance to heat stress. The success of the induction of HSPs by anoxia is in direct relation to the amount of sucrose available, and this in turn relates to how well seedlings will survive under anoxia. HSP transcripts were also detected during seed development and germination, two hypoxia-prone processes, suggesting that hypoxia-induced HSP expression is physiologically relevant. [source] Stationary-phase acid and heat treatments for improvement of the viability of probiotic lactobacilli and bifidobacteriaJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2004M. Saarela Abstract Aims:, To investigate whether sublethal treatments of stationary-phase probiotic cultures enhance their survival during lethal treatments and to adapt these treatments to the fermenter-scale production of probiotic cultures. Methods and Results:, Conditions for acid and heat pretreatments were screened for three Lactobacillus and two Bifidobacterium strains. Strains were sublethally treated both at laboratory scale and at fermenter scale in a strain-specific manner and exposed to a subsequent lethal treatment. At laboratory scale viability improvement was detected in each strain. However, improvement was more pronounced in the Lactobacillus than in the Bifidobacterium strains. At fermenter scale three strains were tested: for the two Lactobacillus strains a marked improvement in viability was obtained whereas for the Bifidobacterium strain the improvement was either minor or not detected. Conclusions:, Development of treatments for viability enhancement of probiotic strains is feasible, but strain-specific optimization is necessary to obtain notable improvements. Significance and Impact of the Study:, Strain-specific treatments were developed for the viability enhancement of stationary-phase probiotic cells both at laboratory and fermenter scale. These results can be utilised in the production of probiotic cultures with improved viability. [source] | ||||||||||