ABSTRACT
Tomato is one of the most important fruits worldwide. It is widely consumed due to its sensory and nutritional attributes. However, like many other industrial crops, it is affected by biotic and abiotic stress factors, reducing its metabolic and physiological processes. Tomato plants possess different mechanisms of stress responses in which hormones have a pivotal role. They are responsible for a complex signaling network, where the antioxidant system (enzymatic and non-enzymatic antioxidants) is crucial for avoiding the excessive damage caused by stress factors. In this sense, it seems that hormones such as ethylene, auxins, brassinosteroids, and salicylic, jasmonic, abscisic, and gibberellic acids, play important roles in increasing antioxidant system and reducing oxidative damage caused by different stressors. Although several studies have been conducted on the stress factors, hormones, and primary metabolites of tomato plants, the effect of endogenous and/or exogenous hormones on the secondary metabolism is still poorly studied, which is paramount for tomato growing management and secondary metabolites production. Thus, this review offers an updated overview of both endogenous biosynthesis and exogenous hormone application in the antioxidant system of tomato plants as a response to biotic and abiotic stress factors.
ABSTRACT
Aiming at producing a reduced fat cheese (RFC) as an alternative to full-fat Panela cheese, a highly consumed fresh Mexican dairy product, thermosonication (TS) processes (24 kHz, 400 W nominal power, 2, 4 and 6 min; 50, 55 and 60 °C) were evaluated to treat WPC (80% protein) blended with reduced-fat milk (1 and 2% fat), which were later LTLT pasteurized. TS blends were compared in terms of their technological properties (water holding capacity-WPC, gel firmness- GF, color, pH and titratable acidity) with those of a regular full fat (3%) LTLT pasteurized milk used as a control. Afterwards, a regression analysis was carried out with the obtained data in order to select the most appropriate conditions for cheesemaking purposes (similar GF, higher WHC with respect to the control), minimize both fat content and TS treatment duration to minimize energy expenses. According to these restrictions, the selected conditions were 1.5% fat milk-WPC blend, TS treated at 60 °C for 120 s; 1% fat milk-WPC blend, TS treated at 50 °C for 120 s and 1% fat milk-WPC blend, 50 °C for 144 s, which allowed preparing low fat cheeses (LFCs). These TS treatments were applied in a larger scale to elaborate Panela-type LFCs comparing different technological properties (cheese yield, syneresis, water content, texture profile analysis, color and titratable acidity) with those of a full fat variety, at day 1 and during 14 days of refrigerated storage. Results showed similar texture profiles of LFC cheeses and full fat milk cheeses throughout their storage period with significant changes in composition parameters (higher moisture, protein and salt contents, with low fat percentages), syneresis, selected color parameters (hue, b*), with no observed changes in cheese yield, TA and pH during cheese storage. These promising results are encouraging to develop LFCs with no physicochemical or technological defects using novel processing techniques that may help reducing calorie consumption without compromising sensory acceptability.
Subject(s)
Cheese/analysis , Dietary Fats/analysis , Food Quality , Sonication , Temperature , Whey Proteins/chemistryABSTRACT
RESUMEN Objetivo Evaluar el efecto de la aplicación de métodos combinados para incrementar la vida en anaquel de agua de coco. Métodos El agua de coco fue obtenida de comercios no establecidos en la Ciudad de Puebla, México. El agua de coco fue tratada con luz ultravioleta-C, vainillina o cinamaldehído y almacenada a 5 y 22°C. Se evaluó el efecto de estas tecnologías sobre el crecimiento microbiano de bacterias mesófilas aerobias, mohos y levaduras. Resultados El tratamiento con luz ultravioleta-C redujo la carga microbiana de bacterias mesófilas aerobias y mohos y levaduras en 3,2 y 2,9 ciclos logarítmicos, respectivamente. Durante el almacenamiento del agua de coco, la combinación de luz ultravioleta-C, cinamaldehído y baja temperatura mantuvo una carga microbiana en ambos grupos de microorganismos por debajo de 10 UFC/mL, durante 30 días. Conclusión La aplicación de métodos combinados puede ser una alternativa a bajo costo para la conservación de agua de coco.
ABSTRACT Objective To evaluate the effect of combined methods for increasing the shelf life of coconut water. Methods Coconut water was obtained from non-established commerce of Puebla City, Mexico. Coconut water was treated with ultraviolet-C light, vanillin or cinnamaldehyde, and stored at 5 and 22°C. The effect of combined methods was evaluated in the growth of aerobic mesophiles and molds plus yeasts. Results Ultraviolet-C light treatment reduced the microbial load of aerobic mesophiles and molds plus yeast in 3,2 and 2,9 log cycles, respectively. In stored coconut water, the combination of ultraviolet-C light, cinnamaldehyde and low temperature maintained the microbial load in both groups of microorganisms under 10 CFU/mL for 30 days. Conclusion Combined methods may be an alternative at a low cost for the conservation of coconut water.
