Food packaging materials are commonly derived from petroleum that increases global contamination; this raises the interest to evaluate raw material from renewable sources such as whey protein for the development of packaging materials, especially to produce active films. This research aimed to evaluate whey protein-based film properties when natamycin, nanoemulsioned α-tocopherol, or both were added. An oil-in-water (O/W) nanoemulsion of antioxidant (α-tocopherol) was prepared by microfluidization technique. Four films were prepared with different levels of natamycin and nanoemulsified α-tocopherol and were characterized in terms of physicochemical, mechanical, optical-properties, water vapor barrier, FTIR, microstructure, antioxidant and antimicrobial activity. The natamycin, nanoemulsified α-tocopherol, or both did not modify the moisture content of the films. Moreover lead to a significant reduction of tensile strength and elastic modulus, while presenting growth in the elongation at break. Film opacity, the total color difference, the UV-Vis light barrier, and the water vapor permeability values increased when compounds were incorporated into the film. The microstructure studies showed uniformly distributed porosity throughout the films. The addition of nanoemulsioned α-tocopherol into whey protein-based films provoked antioxidant activity and the addition of natamycin produced films with effectivity against C. albicans, P. chrysogenum, and S. cerevisiae, allowing develop a material appropriate for use as active food packaging.
Respiration of cut mango (Mangifera Indica L.) cv. Tommy Atkins was studied using the closed system method at three temperatures (4, 20 and 35 °C). Two models were used to estimate the gas concentration, which were adjusted through non-lineal regression algorisms using Matlab R2011a software. Three mathematic models, a model based on Michaelis-Menten's enzymatic kinetics, and two models based on regression analysis, in one of which a saturation equation was included as a new proposal in this field, were set to predict the substrate respiration rate. Results made evident the positive effect of temperature on mango respiration rate. The model with the best adjustment to mango respiration rate was Michaelis-Menten's with an adjusted correlation coefficient of 0.9811 and 0.9747 for CO2 and O2 respectively, with a relative mean error lower than 10%.
Resumen Medir la tasa de respiración de los productos frescos es esencial para el correcto diseño de sistemas de envasado. Para tal efecto, las tasas de consumo de O2 y producción de CO2, suelen ser medidas como datos iniciales del comportamiento del sistema. El objetivo del presente trabajo fue modelar la respiración del mango entero (Mangifera indica L), variedad Tommy Atkins en un sistema cerrado (SC) a tres temperaturas (4, 25 y 35°C) y 90 h en almacenamiento. Inicialmente se ajustó un modelo matemático para predecir la concentración de gases en función del tiempo. Con esta información, se ajustaron dos modelos para predecir las velocidades de respiración. Un modelo de regresión y otro basado en la cinética de inhibición enzimática de Michaelis-Menten (MM). Se ajustó además una ecuación tipo Arrhenius para evaluar el efecto de la temperatura sobre la tasa de respiración y un modelo semi-empírico que predice el efecto del tiempo y la temperatura simultáneamente. Los resultados mostraron que el modelo de MM y Arrhenius obtuvieron los mejores ajustes. En este sistema la velocidad de respiración del mango presenta una dependencia directa con la temperatura y la concentración de los gases, viéndose inhibida por la presencia de CO2 y favorecida por el O2.
Nowadays, the application of non‐destructive techniques in food engineering is arising. Fourier transform infrared spectroscopy (FTIR) combined with chemometric tools show potential in evaluation of food materials. The aim of this work was to determine the applicability of FTIR profiles and chemometric tools to predict the mechanical properties of whey protein‐based film (WPF). A WPF solution was prepared using whey protein concentrate/distilled‐water/glycerol in (10/85/5% wt/wt) respectively. Then, the films were aged at 30°C/5 days and 60% RH. Each day, 10 pieces were evaluated, obtaining their FTIR profiles (4000–650 cm−1), tensile strength (TS), elongation at break (EB), and elastic modulus (EM). Principal component analysis‐multilinear regression (PCA‐MLR) and partial least square regression (PLSR) were developed using the K‐fold cross‐validation technique. For EB and EM, the coefficient of correlation (R2) and root means squared error (RMSE) were above 0.8990 and under 0.5250 (Full PLSR) and 0.8730 and 0.1378 (Optimized PLSR), unlike to TS presented R2 and RMSE values lower than 0.2160 and 2.5247, similar to PCA‐MLR models with values lower than 0.2050 and 0.1889, respectively (for all variables). In this sense, the use of FTIR profiles coupled to chemometric tools could be adequate to predict some properties in WPFs during aging. Practical applications This research presents a practical way for mechanical properties evaluation in films by means of Fourier Transform Infrared Spectroscopy (FTIR) coupled to chemometric tools. This new method could be useful for rapid monitoring of textural properties and characterization of films for food packaging.
El objetivo de esta investigación es modelar la velocidad de respiración (VR) del mango (Mangifera indica L.), variedad Tommy Atkins, cortado osmodeshidratado a tres temperaturas en un sistema cerrado. Mangos cortados en cubos se osmodeshidrataron en solución de sacarosa (60 ° Brix) a 323.15 K durante 4 horas. La concentración de O2 y CO2 fue medida en las condiciones establecidas. La VR experimental fue calculada y ajustada a los modelos de regresión (M-R), Michaelis-Menten (M-M), Arrhenius y a un modelo global semiempírico que predice la concentración de gases en función del tiempo y temperatura. Los resultados muestran que la VR predicha con M-M presentó mayores ajustes comparado con M-R. La energía de activación fue 55.76 y 31.42 kJg -1 h -1 para O2 y CO2, respectivamente. El modelo global predijo la concentración del O2 (R 2 = 0.96) y del CO2 (R 2 = 0.96). Se concluye que la osmodeshidratación disminuyó la VR experimental comparada con otros estudios en mango entero y cortado fresco.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.