scholarly journals Thermodynamic Properties and State Diagram of Gum Ghatti-Based Edible Films: Effects of Glycerol and Nisin

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 449 ◽  
Author(s):  
Pingping Zhang ◽  
Ya Zhao ◽  
Xin Zhang ◽  
Lanlan Zhu ◽  
Zhongxiang Fang ◽  
...  

In this present study, the thermodynamic and thermal properties of glycerol and nisin-incorporated gum ghatti (GG, Anogeissus latifolia)-based films were determined. The films exhibited type III isotherm behaviors. Moisture content (MC) of films was increased with increasing water activity (aw) and decreased with higher temperature. The incorporation of glycerol and nisin increased the sorption ability of GG films. The net isosteric heat of adsorption (qst) and differential entropy (Sd) were decreased with increasing MC, showing an exponential negative correlation between them. Spreading pressure (φ) was increased with increasing aw, but decreased with higher temperature. This incorporation of glycerol and nisin increased the qst, Sd and φ of the GG films. The sorption behaviors were enthalpy-driven and non-spontaneous processes. The glass transition temperature (Tg), critical MC and aw of the films were decreased, and increased respectively with the incorporation of glycerol and nisin. This work provides a theoretical basis for the application of edible films in fresh food preservation.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seyed Mohammad Davachi ◽  
Neethu Pottackal ◽  
Hooman Torabi ◽  
Alireza Abbaspourrad

AbstractThere is growing interest among the public and scientific community toward the use of probiotics to potentially restore the composition of the gut microbiome. With the aim of preparing eco-friendly probiotic edible films, we explored the addition of probiotics to the seed mucilage films of quince, flax, and basil. These mucilages are natural and compatible blends of different polysaccharides that have demonstrated medical benefits. All three seed mucilage films exhibited high moisture retention regardless of the presence of probiotics, which is needed to help preserve the moisture/freshness of food. Films from flax and quince mucilage were found to be more thermally stable and mechanically robust with higher elastic moduli and elongation at break than basil mucilage films. These films effectively protected fruits against UV light, maintaining the probiotics viability and inactivation rate during storage. Coated fruits and vegetables retained their freshness longer than uncoated produce, while quince-based probiotic films showed the best mechanical, physical, morphological and bacterial viability. This is the first report of the development, characterization and production of 100% natural mucilage-based probiotic edible coatings with enhanced barrier properties for food preservation applications containing probiotics.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 767
Author(s):  
Elsa Díaz-Montes ◽  
Roberto Castro-Muñoz

Some of the current challenges faced by the food industry deal with the natural ripening process and the short shelf-life of fresh and minimally processed products. The loss of vitamins and minerals, lipid oxidation, enzymatic browning, and growth of microorganisms have been the main issues for many years within the innovation and improvement of food packaging, which seeks to preserve and protect the product until its consumption. Most of the conventional packaging are petroleum-derived plastics, which after product consumption becomes a major concern due to environmental damage provoked by their difficult degradation. In this sense, many researchers have shown interest in edible films and coatings, which represent an environmentally friendly alternative for food packaging. To date, chitosan (CS) is among the most common materials in the formulation of these biodegradable packaging together with polysaccharides, proteins, and lipids. The good film-forming and biological properties (i.e., antimicrobial, antifungal, and antiviral) of CS have fostered its usage in food packaging. Therefore, the goal of this paper is to collect and discuss the latest development works (over the last five years) aimed at using CS in the manufacture of edible films and coatings for food preservation. Particular attention has been devoted to relevant findings in the field, together with the novel preparation protocols of such biodegradable packaging. Finally, recent trends in new concepts of composite films and coatings are also addressed.


2014 ◽  
Vol 116 (7) ◽  
pp. 1194-1204 ◽  
Author(s):  
Wayne Martindale

Purpose – The purpose of this paper is to define the sustainability attributes of frozen and fresh food consumption in a typical household. The reason for writing this paper is that food preservation is often overlooked when developing sustainability strategies. Design/methodology/approach – This study uses established carbon footprint data for specific food types and consumer survey data to determine how consumers use fresh and frozen products in the home. Consumption and waste data for 83 households was obtained using a combination of narrative and graphical association questions. Findings – The results show greenhouse gas emissions associated with a diets containing frozen food are reduced because 47 per cent less frozen foods is wasted as compared to fresh foods with a typical household wasting 10.4 per cent of fresh food and 5.9 per cent frozen food. Research limitations/implications – This research has highlighted the importance of understanding the waste impacts of catering and food service consumption outside the home. Practical implications – This research will guide future product development for frozen foods with regard to dietary planning and portion control. Social implications – The cost and sustainability benefits of meal planning are identified and these will inform policy making and education to improve dietary choices. Originality/value – This work extends the scope of current consumer surveys that assess quality, value and taste attributes to sustainability criteria and it will enable collaboration between fresh and frozen product categories to deliver sustainable dietary options.


Molekul ◽  
2018 ◽  
Vol 13 (2) ◽  
pp. 114
Author(s):  
Margareta Novian Cahyanti ◽  
Alvama Pattiserlihun

The moisture sorption isotherm data of gaplek flour fortified with red bead tree seed stored in a chamber, the relative humidity of chamber ranging from 10% to 97% regulated using a saturated salt solution, was determined at three temperatures 25°, 35°, and 45 °C. The experimental data used to determine the thermodynamic functions were isosteric heat of sorption, sorption entropy, and free energy changes. The sorption isosteric heats were determined by the application of the Clausius–Clapeyron equation. Isosteric heats of adsorption increased to maximum level and then declined with increase of moisture content. Adsorption entropy increased to maximum level and then declined with the increase of moisture content. The free energy changes increased with increase in moisture content. The spreading pressure increased with increasing water activity.


2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Indira Dey Paul ◽  
Madhusweta Das

The present work aimed to: i) find the suitable proportion, based on sensory evaluation, of microwave-convective hot air dried jamun (Syzygium cumini L.) pulp and seed kernel powder to be mixed for the preparation of jamun powder (JP); ii) generate and model the moisture sorption isotherm (MSI) of JP; and iii) estimate net isosteric heat of sorption (qst), spreading pressure (φ), net integral enthalpy (Qin), and net integral entropy (Sin). To formulate JP, the proportion (w/w, db) comprising 2% kernel and 98% pulp powder was the most desirable. The Peleg model was the best fit to MSI of JP. The qst decreased following linear relationship from 11.02 kJ. mol-1 at 5% equilibrium moisture content (EMC) to 0.27 kJ. mol-1 at 30% EMC. The φ increased with increase in water activity and decreased with increase in temperature from 25 ºC to 35 ºC, and the values of φ at 45 ºC were even higher than at 25 ºC. Net integral enthalpy (Qin) initially decreased till 6% moisture content in JP and displayed an increasing trend with further increase in moisture content. On the contrary, Sin, kept on decreasing continually with increasing moisture content. The moisture zone of 7-11% was considered safe for storage for storage of JP within the temperature range of 45-25 ºC.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Rachida Ouaabou ◽  
Said Ennahli ◽  
Chira Di Lorenzo ◽  
Hafida Hanine ◽  
Aadil Bajoub ◽  
...  

Understanding sorption isotherms is crucial in food science for optimizing the drying processes, enhancing the shelf-life of food, and maintaining food quality during storage. This study investigated the isotherms of sweet cherry powder (SCP) using the static gravimetric method. The experimental water sorption curves of lyophilized sweet cherry powder were determined at 30°C, 40°C, and 50°C. The curves were then fitted to six isotherm models: Modified GAB, Halsey, Smith, Oswin, Caurie, and Kühn models. To define the energy associated with the sorption process, the isosteric sorption heat, differential entropy, and spreading pressure were derived from the isotherms. Among the six models, the Smith model is the most reliable in predicting the sorption of the cherry powder with a determination coefficient (R2) of 0.9978 and a mean relative error (MRE) ≤1.61. The values of the net isosteric heat and differential entropy for the cherry increased exponentially as the moisture content decreased. The net isosteric heat values varied from 10.63 to 90.97 kJ mol−1, while the differential entropy values varied from 27.94 to 273.39 J. mol−1K−1. Overall, the enthalpy-entropy compensation theory showed that enthalpy-controlled mechanisms could be used to regulate water adsorption in cherry powders.


2016 ◽  
Vol 175 ◽  
pp. 1-7 ◽  
Author(s):  
Maria D. De'Nobili ◽  
Marcelo Soria ◽  
Manuela R. Martinefski ◽  
Valeria P. Tripodi ◽  
Eliana N. Fissore ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Anna Zimoch-Korzycka ◽  
Antoine Rouilly ◽  
Łukasz Bobak ◽  
Andrzej Jarmoluk ◽  
Michał Korzycki

This work characterizes biological, physical, and chemical properties of films formed from an aqueous solution of hydroxypropyl methylcellulose (HPMC), with different concentrations of chitosan (CH) and bioactive cystatin/lysozyme preparation (C/L). The properties of biocomposites were examined by Dynamic Mechanical Analysis (DMA), Fourier’s transfer infrared spectroscopy (FTIR), water vapour permeability (WVP), and tensile testing. Antimicrobial activity againstMicrococcus flavus,Bacillus cereus,Escherichia coli,Pseudomonas fluorescens, andCandida famatawas conducted. Films glass transition and storage modulus were dependent on the C/L and CH concentration. Modulus values decreased during the temperature scan and with higher reagents levels. An increase of CH and C/L concentrations in the films resulted in a decrease in tensile strength from 2.62 to 1.08 MPa. It suggests the hydrolyzing influence of C/L, also observed in smaller peak size ofαrelaxation. C/L addition caused shiftingTgto higher temperature. DMA and FTIR analysis proved that HPMC and CH are compatible polymers. Water resistance was improved with rising CH concentration from1.08E-09to7.71E−10 g/m∗s∗Pa. The highest inhibition zone inM. flavusandC. famatawas recorded at the highest concentration of CH and C/L.


2016 ◽  
Vol 76 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Wayne Martindale

While we state it seems unthinkable to throw away nearly a third of the food we produce, we still continue to overlook that we are all very much part of this problem because we all consume meals. The amount of food wasted clearly has an impact on our view of what we think a sustainable meal is and our research suggests food waste is a universal function that can help us determine the sustainability of diets. Achieving sustainability in food systems depends on the utilisation of both culinary skills and knowledge of how foods make meals. These are overlooked by the current food waste debate that is concerned with communicating the problem with food waste rather than solutions to it. We aim to change this oversight with the research presented here that demonstrates the need to consider the role of food preservation to reduce food waste and the requirement for new marketing terms associated with sustainability actions that can be used to stimulate changes in consumption behaviours. We have chosen frozen food to demonstrate this because our research has shown that the use of frozen foods results in 47 % less household food waste than fresh food categories. This has created a step-change in how we view food consumption and has stimulated consumer movements that act across different products and supply chains to enable the consumption of the sustainable meal.


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