Chemical, physical and sensory properties of Vienna sausages formulated with a starfruit dietary fiber concentrate.

The use of a starfruit dietary fiber concentrate (SDFC) as a novel ingredient in Vienna sausages was investigated. A constrained mixture design was followed to evaluate the effect of different proportions of SDFC (0-10%), pork meat (0-100%) and turkey meat (0-100%) on the shear force, shrinkage, color, residual nitrite, moisture and polyphenol contents of sausages. Moreover, a chemical, physical and sensory characterization of the optimized formulations was performed. The cubic model equations demonstrated that the SDFC in mixture with pork or turkey meat had a reducing effect on nitrites, moisture, shear force and shrinkage, while there was an increase on the polyphenol concentration as the increase of SDFC proportion in the formulations. The optimization resulted in Vienna-type sausages formulated with a ternary mixture of pork/turkey meat and high SDFC proportion (7.4-8.4%). These products had high total dietary fiber content (11.04-17.79%) and antioxidant polyphenols, low residual nitrite content, shrinkage and red color. They presented good taste, color and texture attributes, and were sensory acceptable. This study demonstrated that enrichment of Vienna-type sausages with SDFC in mixture with pork/turkey meat is a way to obtain potential functional meat products with high antioxidant dietary fiber content, reduced in nitrites, and good physical and sensory properties.

[Efficacy of disinfection treatments using essential oils and ultrasound on tomato fruits inoculated with Escherichia coli and impact on antioxidant activity]. / Eficiencia de la desinfección con aceites esenciales y ultrasonido sobre Escherichia coli inoculada en frutos de tomate y el impacto sobre la actividad antioxidante.

Fresh produce often harbors a great number of microorganisms; hence, its growing demand may constitute a risk for consumers. The aim of this study was to evaluate the efficacy of several disinfection procedures against enterotoxigenic Escherichia coli (ETEC) inoculated on tomato fruits and the conservation of the antioxidant properties of these disinfected fruits. Fruits were immersed for 5 or 10min in oregano or thyme essential oil dispersions (5, 10ppm), with or without ultrasound treatment. Antioxidant activity of disinfected fruits was determined as the ability to scavenge 2,2-diphenyl-1-pricrylhydrazyl (DPPH) radicals and was reported as percentage of inhibition (%I). The most efficient disinfectant treatments showing significant differences (p≤.05) between the reductions log10 CFU/g (S) of ETEC were those using 10ppm oregano for 10min, with S=3.05 in individual treatments and S=4.03 in mixed treatments. The highest %I was obtained with individual sonication treatments (69.52 and 72.48), while in combined treatments the %I values increased with thyme oil 5ppm and ultrasound for 5min (51.27%) and 10min (53.31%).

Use of high-intensity ultrasound as a pre-treatment for complex coacervation from whey protein isolate and iota-carrageenan.

The aim of this work was to evaluate the influence of high intensity ultrasound (HIUS) treatment on the molecular conformation of whey protein isolated (WPI) as a previous step for complex coacervation with iota carrageenan (IC) and its effect on the surface functional properties of complex coacervates (CC). Both biopolymers were hydrated (1% w/w) separately. A WPI suspension was treated with an ultrasonic bath (40 kHz, 600 W, 30 and 60 min, 100% amplitude). A non-sonicated protein was used as a control. Coacervation was achieved by mixing WPI and IC dispersions (10 min). FTIR-ATR analysis (400-4000 cm-1) detected changes after sonication on WPI secondary structure (1600-1700 cm-1), electrostatic interaction between WPI and IC by electronegative IC charged groups like sulfate (1200-1260 cm-1), anhydrous oxygen of the 3.6 anhydro-D-galactose (940-1066 cm-1) and the electropositive regions of WPI. Rheology results showed pseudoplastic behavior of both IC and WPI-IC with a significant change in viscosity level. Further, HIUS treatment had a positive effect on the emulsifying properties of the WPI-IC coacervates, increasing the time foaming (30 min) and emulsion stability (1 month) percentage. HIUS and complex coacervation proved to be an efficient tool to improve the surface functional properties of WPI.

Uncovering the Role of Hormones in Enhancing Antioxidant Defense Systems in Stressed Tomato (Solanum lycopersicum) Plants.

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.

Thermosonicated whey protein concentrate blends on quality attributes of reduced fat Panela cheese.

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.

Eficiencia de la desingección con aceites esenciales y ultrasonido sobre Escherichia coli inoculada en frutos de tomate y el impacto sobre la actividad antioxidante / Efficacy of disinfection treatments using essential oils and ultrasound on tomato fruits inoculated with escherichia coli and impact on antioxidant activity

La creciente demanda de frutos frescos puede constituir un riesgo para la salud de los consumidores, teniendo en cuenta la gran variedad de microorganismos que estos suelen albergar. El objetivo del presente estudio fue evaluar la eficacia de varios procedimientos de desinfección sobre Escherichia coli enterotoxigénica (enterotoxigenic E. coli [ETEC]) inoculada en tomate y la conservación de las propiedades antioxidantes de los frutos desinfectados. Los frutos fueron sumergidos durante 5 o 10min en dispersiones de aceites esenciales de orégano o tomillo (5 o 10ppm), combinados o no con la aplicación de ultrasonido. La actividad antioxidante se determinó por la neutralización del radical 2,2-difenil-1-pricrilhidrazil (DPPH) y se reportó como porcentaje de inhibición (%I). Los tratamientos de desinfección más eficaces para una significativa reducción log10 UFG/g (S) de ETEC fueron con 10ppm de aceite de orégano durante 10min, con reducciones S=3,05 en tratamientos individuales y S=4,03 en mixtos. Los %I más altos se lograron con tratamientos individuales con sonicación (69,52 y 72,48) y en tratamientos combinados con aceite de tomillo 5ppm y ultrasonido durante 5 y 10min, con valores de 51,27 y 53,31%, respectivamente

Fresh produce often harbors a great number of microorganisms; hence, its growing demand may constitute a risk for consumers. The aim of this study was to evaluate the efficacy of several disinfection procedures against enterotoxigenic Escherichia coli (ETEC) inoculated on tomato fruits and the conservation of the antioxidant properties of these disinfected fruits. Fruits were immersed for 5 or 10min in oregano or thyme essential oil dispersions (5, 10ppm), with or without ultrasound treatment. Antioxidant activity of disinfected fruits was determined as the ability to scavenge 2,2-diphenyl-1-pricrylhydrazyl (DPPH) radicals and was reported as percentage of inhibition (%I). The most efficient disinfectant treatments showing significant differences (p≤.05) between the reductions log10 CFU/g (S) of ETEC were those using 10ppm oregano for 10min, with S=3.05 in individual treatments and S=4.03 in mixed treatments. The highest %I was obtained with individual sonication treatments (69.52 and 72.48), while in combined treatments the %I values increased with thyme oil 5ppm and ultrasound for 5min (51.27%) and 10min (53.31%)