Shelf Life Of Fresh Vegetables Research Articles

Ultraviolet light food processing: A mini concept

Chemical preservatives, which are added to food to increase shelf life and to guard against diseases that can spread through food borne bacteria, are drawing an increasing amount of criticism from the general public. Alternatives to present preservation methods are being sought to meet customer desires for healthier meals. In contrast to conventional heat processing, ultraviolet light has great promise in the field of food processing. Just a few of its applications include pasteurizing juices, postlethality treating of meats, treating surfaces in touch with food and increasing the shelf life of fresh vegetables. A brief assessment of the working of UV light and its applications is done in this review. In specific this review work highlights the potential application of ultraviolet as an alternative means of preservation of food.

An Inclusive Review on Mucilage: Extraction Methods, Characterization, and its Utilization for Nanocarriers Manufacturing

Mucilages have attracted a lot of study and commercial interest as a result of the growing interest in natural ingredients. Mucilages are polysaccharide hydrocolloids having a wide range of physicochemical and structural properties, as well as functional and health benefits. Plant-derived mucilage has been discovered to be a natural thickening and emulsifier, as well as a substitute for manufactured polymers and chemicals. It is used as an edible coating to increase the shelf life of fresh vegetables and fruits, as well as many other food products, because it is an invisible barrier that separates the surface from the surrounding atmosphere. Mucilage can also be utilised to make nanocarriers in addition to its functional features. The most extensively used traditional and developing extraction and purification procedures are explained in this overview, which is supplemented with information on the important criteria for determining the physicochemical and functional qualities of mucilages. The biodegradable and biocompatible features of these low-cost excipients make them more suitable for the development of innovative formulations. Understanding the ecological, economic, and scientific aspects that influence production, as well as the efficacy of mucus as a multi-directional agent, will allow it to be used in a variety of businesses.
 Keywords: Bioactive compounds, Mucilages, Extraction, Polysaccharides, Food applications, Biopolymers

Biodegradable Films with the Addition of Nanofibers: a Review Focusing on Raw Materials and Analysis

HIGHLIGHTS Starch is promising biopolymer to be used as a biodegradable natural source. The combination of starch with nanocellulose can provide new applications. Glycerol is an additive widely used in the production of biodegradable packaging. Biodegradable films are effective to extend the shelf life of fresh vegetables.

A Comprehensive Review on Plant-Derived Mucilage: Characterization, Functional Properties, Applications, and Its Utilization for Nanocarrier Fabrication.

Easily sourced mucus from various plant parts is an odorless, colorless and tasteless substance with emerging commercial potential in agriculture, food, cosmetics and pharmaceuticals due to its non-toxic and biodegradable properties. It has been found that plant-derived mucilage can be used as a natural thickener or emulsifier and an alternative to synthetic polymers and additives. Because it is an invisible barrier that separates the surface from the surrounding atmosphere, it is used as edible coatings to extend the shelf life of fresh vegetables and fruits as well as many food products. In addition to its functional properties, mucilage can also be used for the production of nanocarriers. In this review, we focus on mucus extraction methods and its use as a natural preservative for fresh produce. We detailed the key properties related to the extraction and preservation of food, the mechanism of the effect of mucus on the sensory properties of products, coating methods when using mucus and its recipe for preserving fruit and vegetables. Understanding the ecological, economic and scientific factors of production and the efficiency of mucus as a multi-directional agent will open up its practical application in many industries.

Effect of biodegradable active packaging with zeolites on fresh broccoli florets.

Most of the food packaging is mainly petroleum-based, and new forms of food packaging have emerged, such as active, intelligent, and biodegradable packaging to extend the shelf life of fresh vegetables. The aim was to develop a biodegradable active packaging and senescence indicator label for fresh broccoli florets (Brassica oleracea L. var. italica), to increase shelf life and to monitor the decay of the vegetable. The biodegradable active packagings (BAP) were produced by blown extrusion containing zeolite as ethylene scavenger, and their mechanical properties, water vapor permeability, and water sorption isotherms were determined. Fresh broccoli florets were packed in perforated and non-perforated BAP and stored at 12°C, and their weight loss, vitamin C content, color, and texture were evaluated during the storage. BAPs were efficient in reducing the metabolism of fresh broccoli florets stored at 12°C, preserving the color, and vitamin C content for 7days. The senescence indicator labels were able to detect CO2 in packages without perforations.

Efficacy of the combined application of oregano and rosemary essential oils for the control of Escherichia coli, Listeria monocytogenes and Salmonella Enteritidis in leafy vegetables

This study assessed the effect of the combined application of essential oils (EOs) from Origanum vulgare L. – oregano (OVEO) and Rosmarinus officinalis L. – rosemary (ROEO), alone or in combination at subinhibitory concentrations, against three pathogenic bacteria that are associated with fresh leafy vegetables: Listeria monocytogenes (L. monocytogenes), Escherichia coli (E. coli) and Salmonella enterica Serovar Enteritidis (S. Enteritidis). The inhibitory effects were evaluated by determining the minimum inhibitory concentration (MIC) and the fractional inhibitory concentration index (FICI) and assessing the viable cell counts in vegetable broth and artificially infected vegetables over time. Still, the effects of the EOs on native spoilage native flora were assessed. The MIC of OVEO was 0.6 μL/mL against the test strains either in single and mixed inoculum. The MIC of ROEO was 5 μL/mL against L. monocytogenes and E. coli and 10 μL/mL against S. Enteritidis in single inocula, whereas it was 10 μL/mL against the mixed inoculum. The FICI of the combined EOs was 0.5 against the mixed bacterial inoculum, which suggested a synergic interaction. The incorporation of OVEO and ROEO alone (MIC) or combined at different subinhibitory concentrations in vegetable broth resulted in a decrease in the viable cell counts of all test strains over 24 h. Similarly, the EOs alone or in the tested combinations reduced the viable cell counts of all test strains in experimentally infected fresh vegetables, besides to decrease the counts of spoiling native flora (mesophilic bacteria, enterobacteria and fungi). These findings reinforce the rational for the use of OVEO and ROEO in combination at subinhibitory concentrations to guarantee the safety and extend the shelf life of fresh vegetables.

Impact of plant essential oils on microbiological, organoleptic and quality markers of minimally processed vegetables

The objectives of this study were to evaluate the efficacy of plant essential oils (EOs) for control of the natural spoilage microflora on ready-to-eat (RTE) lettuce and carrots whilst also considering their impact on organoleptic properties. Initial decontamination effects achieved using EOs were comparable to that observed with chlorine and solution containing oregano recorded a significantly lower initial TVC level than the water treatment on carrots (p < 0.05). No significant differences were found between the EO treatments and chlorine considering gas composition, color, texture and water activity of samples. The sensory panel found EO treatments acceptable for carrots throughout storage, while lettuce washed with the EO solutions were rejected for overall appreciation by Day 7. Correlating microbial and sensory changes with volatile emissions identified 12 volatile quality markers. Oregano might be a suitable decontamination alternative to chlorine for RTE carrots, while the identification of volatile quality markers is a useful complement to sensory and microbiological assessments in the monitoring of organoleptic property changes and shelf-life of fresh vegetables. Industrial relevance: There is industrial demand for natural alternatives to chlorine, which is commonly used for decontamination of fresh produce but which has limitations with respect to antimicrobial efficacy and possible formation of carcinogenic compounds in water. Plant essential oils have proven antimicrobial and other bioactive properties, however their usefulness in foods can be mitigated by their high sensory impact. This study examined the application of EOs for fresh produce decontamination addressing control of spoilage microflora and improving shelf-life characteristics whilst also considering the impact on organoleptic properties. The effectiveness of oregano as a decontamination treatment was comparable with that of chlorine. Carrot discs treated with the EO regimes were acceptable in terms of sensory quality and appreciation, therefore oregano could offer a natural alternative for the washing and preservation of fresh produce. Combining EOs with other natural preservatives might minimize doses and reduce the impact on organoleptic properties of fresh vegetables. © 2008 Elsevier Ltd. All rights reserved.

Failure criteria based on consumers’ rejection to determine the sensory shelf life of minimally processed lettuce

The aims of the present work were to determine failure criteria based on consumers’ rejection to purchase for shelf life estimation of minimally processed lettuce, and to compare criteria for whole and cut lettuce. A trained sensory panel and a consumer panel evaluated samples of whole and cut lettuce leaves packaged in passive modified atmosphere. In order to determine failure criteria to estimate sensory shelf lives, sensory attribute intensities corresponding to 25% consumers’ rejection to purchase percentage were calculated using logistic regressions. Failure criteria values were lower for cut lettuce than for whole leaves for all the evaluated attributes, suggesting that consumers reacted differently towards whole and cut lettuce leaves, being stricter towards cut lettuce than towards whole lettuce leaves. These results indicate that sensory limits depended on the product considered and therefore a unique criterion should not be used to estimate the shelf life of both cut lettuce and whole lettuce leaves. Twenty-five percent of the consumers would refuse to purchase cut lettuce if the intensity of the evaluated defects was over 10% of the measuring scale, whereas scores of 25% of the scale were needed to achieve a 25% of consumer rejection in the case of whole leaves. These failure criteria were stricter than those traditionally used for sensory shelf life estimation of minimally processed lettuce, which might assure the products’ quality at the end of its shelf life. Results of the present study showed the importance of performing consumer studies in order to establish proper criteria to estimate the shelf life of fresh vegetables.