Use Of Edible Coatings Research Articles

The nutraceutical quality of tomato fruit during domestic storage is affected by chitosan coating

Fruits and vegetables are highly perishable foods which usually undergo a gradual loss of nutraceuticals during storage. Chitosan-based edible coatings are extensively studied thanks to antimicrobial activity and great potential to extend the shelf life. However, little information is presently available on the nutraceutical quality of chitosan-coated products. The present study is addressed to evaluate accompanied by a delayed degradation of some phenolic compounds during storage. These results indicate that chitosan coating is effective in maintaining the quality parameters, the coated fruit showed less weight loss (−16%) and more firmer (+40%) than control fruit, chitosan-coated tomato emitted significantly lower ethylene (−41%) than control, and slowing down the nutraceutical loss occurring in postharvest, mainly of the lycopene, main carotenoid, found in tomato fruits. These results indicate that chitosan coating is effective in slowing down the nutraceutical loss occurring in postharvest, thus representing a promising tool to preserve bio-protective phytochemicals during fruit conservation. Practical applications During storage and domestic conservation, the nutraceutical quality of fruits and vegetables usually decreases and can undergo deterioration due to physiological disorders and mechanical damages. In the last decade, use of edible coatings has attracted interest as a promising technology to prolong the shelf life of particularly perishable foods. These coatings act as protective barriers decreasing transpiration rate and gas transfer across the product surface, thus promoting the maintenance of nutritional quality.

Effect of Aloe Vera Gel and Gum Arabic Coating on Shelf Life and Nutrient Content of Green Capsicum (<i>Capsicum annuum L</i>)

Capsicum, a common name of Capsicum annuum L., is an annual herbaeceous plant of the Capsicum genus belonging to the Solanaceae family. India contributes to one fourth of the world production of capsicum with an average annual production of 0.9 million tons. About 1.67 million metric tonnes of capsicums was produced in India during the period of 2013-2014. Capsicums are highly perishable and harvested over a restricted period. Therefore the need for proper storage techniques arises to regulate marketing and to provide high-quality produce throughout the year. Edible coatings are thin layer of edible materials formed directly onto the surface of the food that can be eaten as part of the whole product without bringing any undesirable change in the foodstuff. Use of edible coatings as an alternative post harvest preservation technique for fruits and vegetables has been gaining an increasing interest. Green capsicum was coated with two different coatings made of gum Arabic and Aloe vera gel and were kept at refrigerated and ambient storage for a period of 25 days and were observed for the post harvest quality characteristics. It was seen that these edible coatings were found to be effective and acceptable in extending the shelf life of capsicum in both refrigerated as well as ambient conditions. However, the capsicums stored in refrigerator were found to be marketable for a long period of time. The edible coatings showed remarkable retention of nutrients during storage.

Recubrimientos a base de almidón y pectina de plátano ‘Pera’ (Musa ABB), y quitosano aplicados a frutos de mango ‘Ataulfo’ en postcosecha

The development of new postharvest technologies, which prolong useful fruit life and are also biodegradable, has promoted the use of edible coatings, prepared based on polysaccharides obtained from nonconventional sources, such as the starch and pectin in banana fruits. The objective of this study was to evaluate the effects of coatings based on starch and pectin from ‘Pear’ banana, as well as chitosan applied to ‘Ataulfo’ mango fruit. Coverings with 1 % starch and others with 1 % pectin were applied by immersion to mango fruits at physiological maturity; fruits were then stored for 12 days at 10 ± 2°C, plus another 9 days at 22 ± 2°C. The assessed variables were: weight loss (%), color (L*, a*, b*), firmness (kgf∙cm-2), total soluble solids (°Brix), and titratable acidity (%). ‘Ataulfo’ mango fruits covered with starch from ‘Pear’ banana (Musa ABB) showed greater firmness (3.34 kgf∙cm-2) and a high content of total soluble solids (16.96 °Brix), compared to the control fruits (2.26 kgf∙cm-2 and 15.8 °Brix, respectively); this coating extended the postharvest period to 21 days. The edible coatings did not affect the cuticle color of ‘Ataulfo’ mango fruits and retained their typical yellow color

Organic ‘Tommy Atkins’ Mango Postharvest Quality When Treated with Biofilms Enriched by Spirulina platensis

The use of edible coatings has been extensively explored for coating fruits and vegetables to minimize moisture loss and reduce respiration rates, and giving bright and attractive appearance. The objective of this study was to evaluate the mango postharvest quality of 'Tommy Atkins' organic, coated with cassava starch and corn starch enriched with Spirulina platensis. The experiment was conducted in a completely random­ized design in split plot in time, having in the plots biofilms (B), and the subplots, the sampling throughout the storage time. Biofilms (B) were: B1 (without coating); B2 (3% of cassava starch); B3 (3% corn starch); B4 (3% Spirulina powder); B5 (3% starch plus 3% Spirulina powder cassava) and B6 (3% cornstarch plus 3% Spirulina powder). The fruits were stored at 10 °C and 63% RH, where they remained for 0, 3, 6, 9 and 12 days, each range, plus a day to 21.2 °C and 51% RH. The B5 coating showed an increase in soluble solids (SS) until the eighth day and subsequent reduction with storage breakthrough. The fresh weight loss varia­bles (PMF) and flesh firmness decreased their values with storage advancement in all treatments. However, it was concluded through research that the treatment was more efficient was the B6, which provided an increase in soluble solids at around 30%, 15 N flesh firmness and loss of weight less than 4% at the end storage and a higher content of vitamin C (25 mg 100 g -1 ) to 11 days of storage.

USO DE REVESTIMENTO COMESTÍVEL PARA EXTENSÃO DA VIDA ÚTIL DA GOIABA ‘PEDRO SATO’

A goiaba possui intensa atividade metabólica, requerendo o uso de tecnologias pós-colheita para extensão de sua vida útil e manutenção da qualidade. Como é fruto que se consome com a casca, a aplicação de revestimento comestível é uma tecnologia de modificação da atmosfera passível de ser implementada. Objetivou-se, com esse trabalho, avaliar índices de qualidade pós-colheita de goiaba ‘Pedro Sato’, tais como vitamina C, licopeno, β-caroteno, glicose, frutose, sacarose, etc., submetida a três diferentes revestimentos comestíveis (à base de amido de mandioca, alginato de sódio ou carboximetilcelulose) e armazenamento refrigerado à 10 oC. Independentemente do tratamento aplicado, as goiabas ‘Pedro Sato’ alcançaram maiores teores de vitamina C após o armazenamento prolongado de 22 dias. Por outro lado, o uso de revestimentos comestíveis à base de amido e alginato foram eficientes em retardar o amadurecimento das goiabas ‘Pedro Sato’ armazenadas por quatro dias sob refrigeração, seguidos de três dias em temperatura ambiente. As goiabas revestidas com amido de mandioca apresentaram os maiores teores de licopeno (ação antioxidante) e de β–caroteno (precursor da vitamina A no organismo humano), nos períodos de armazenamento mais prolongados, podendo-se recomendar este revestimento comestível para o armazenamento desse fruto, para que se obtenha maior retenção de importantes atributos de sua qualidade.

Edible films as carrier for lactic acid bacteria

The use of edible coatings and films formulated with bioactive compounds in food products in order to convey new functionalities or extend shelf-life opens new possibilities as a carrier for functional lactic acid bacteria. In this work the main objective was to study the stability of probiotic microorganisms, viz. Bifidobacterium animalis Bb-12® and Lactobacillus casei-01, in edible film formulations based on whey protein isolate (WPI).The results demonstrated a loss of bacterial cell viability of ca. 3 log cycles (reaching 106 CFU/g film) until 60 d at both 23 and 4 °C, noting that the most marked decrease was at 23 °C for both strains. Bifidobacterium animalis Bb-12® remained viable for a longer period of time and with less decrease in its cell numbers (108 CFU/g film).Physical properties, namely color, water activity, thickness, young’s modulus, tensile strength, elongation at break and the molecular structure of WPI films were maintained stable throughout the storage period at both temperatures tested.Edible films incorporated with probiotics can be good carriers for these to be ingested together with food products.

Effect of chitosan and sodium alginate edible coatings on the postharvest quality of fresh-cut nectarines during storage

Introduction. The use of edible coatings could be a new technological alternative to maintain fruit quality during cold storage. The objective of this work was to determine the effects of different coatings, alone or in conjunc- tion, on the quality of fresh-cut nectarines during storage. Materials and methods. Nectarines (Prunus persica L.) cv. Big Top were studied under three different coatings: 2% acid-soluble chitosan, 1.5% sodium alginate, and a solution with 3% chitosan and 2% sodium alginate. Slices were then sealed in polyethylene plastic bags and stored at 4 ◦ C and 95% RH for 9 days. Titratable acidity, soluble solids content, firmness, weight loss, color, browning potential and polyphenol oxidase activity were determined. Yeasts and molds were also monitored. Results and discussion. Nec- tarine firmness was maintained equally in all analyzed groups. The color parameter L* showed a tendency to decrease with the increasing length of storage, with lower values in alginate- and alginate + chitosan-coated fruits. The chitosan coating decreased the metabolism activity of fruit during the cold storage without significant changes in the fruit quality (lightness and total soluble solid content). The chitosan coating also controlled the growth of microorganisms. Conclu- sion. The chitosan coating appears to be a promising preservation alternative and an effective method to improve the quality and shelf life of fresh-cut nectarines in marketing conditions.

Perspectives on Utilization of Edible Coatings and Nano-laminate Coatings for Extension of Postharvest Storage of Fruits and Vegetables

It is known that in developing countries, a large quantity of fruit and vegetable losses results at postharvest and processing stages due to poor or scarce storage technology and mishandling during harvest. The use of new and innovative technologies for reducing postharvest losses is a requirement that has not been fully covered. The use of edible coatings (mainly based on biopolymers) as a postharvest technique for agricultural commodities has offered biodegradable alternatives in order to solve problems (e.g., microbiological growth) during produce storage. However, biopolymer-based coatings can present some disadvantages such as: poor mechanical properties (e.g., lipids) or poor water vapor barrier properties (e.g., polysaccharides), thus requiring the development of new alternatives to solve these drawbacks. Recently, nanotechnology has emerged as a promising tool in the food processing industry, providing new insights about postharvest technologies on produce storage. Nanotechnological approaches can contribute through the design of functional packing materials with lower amounts of bioactive ingredients, better gas and mechanical properties and with reduced impact on the sensorial qualities of the fruits and vegetables. This work reviews some of the main factors involved in postharvest losses and new technologies for extension of postharvest storage of fruits and vegetables, focused on perspective uses of edible coatings and nano-laminate coatings.

Physicochemical Behavior of Zinc-Fortified, Sodium Caseinate-Based, Edible-Coated Apricots during Storage in Controlled Atmosphere

Edible coatings are one of the efficient tools to reduce the postharvest losses and ability to incorporate various functional additives. Purposely, current research is an attempt to add fortificants and improve shelf life of fresh apricots using zinc as edible coatings. To increase zinc density, sodium caseinate-based coatings (1 and 2%) fortified with ZnO (20 and 40 ppm) were applied followed by storage in controlled climate chamber. During storage, various quality parameters were assessed to estimate fortificant retention and shelf life extension. Resultantly, coating mixture containing 2% sodium caseinate fortified with 40 ppm ZnO proved to be the best among other treatments. It was deduced that the higher level of sodium caseinate in coating formulations behaved positively in preserving the quality attributes of fruit and zinc retention. Practical Applications The current study was aimed at exploring the potential utilization of edible coatings as a carrier of zinc coated over apricots to curtail the predicament of hypozincemia, i.e., zinc deficiency. Purposely, sodium caseinate-based, zinc-fortified edible coatings were prepared and applied on the surface of apricots. This treatment makes the apricots zinc dense as well as improves the shelf life of the apricots as edible coatings hinder the unnecessary water and gas transfers. The study explored the potential of the sodium caseinate-based edible coatings as a promising tool to deliver added zinc salt and improved shelf life of the coated fruit. The physicochemical attributes of apricots were preserved by the utilization of these coatings and nutritionally higher zinc levels were found available for the body. Additional research work is still needed to explore more aspects of the coatings and coating fortificant mixture interactions to confirm the potential use of edible coatings as a carrier of deficient mineral salts.

Combination irradiation treatments for food safety and phytosanitary uses

Purpose of the review: Combination of irradiation treatment with other preservation techniques is of potential importance in enhancing the effectiveness and reducing the energy or dose requirement for destroying food borne illness and spoilage organisms while retaining or improving product quality. Phytosanitary irradiation to control quarantine pests, particularly insects, in traded fresh commodities may also benefit from combination with other disinfestation techniques to enhance effectiveness, and to reduce costs, treatment time, and product damage. Main findings: Combined preservation treatments can be beneficial to eliminate pathogenic bacteria due to the synergistic or additive effect of the treatments. It also permits less extreme use of a single treatment which may protect the sensory quality of the foods. Combination with modified atmosphere packaging (MAP), refrigeration, freezing or heating has great potential for improving the quality and the safety of fresh and processed foods. Irradiation and heat treatments reduce the numbers of pathogenic bacteria and the level of normal flora, while MAP and cold suppresses the growth of the survivors during subsequent storage. The use of natural antimicrobials at concentrations that do not affect the sensory qualities can increase the relative sensitivity of bacteria by >4-fold and can reduce the radiation dose necessary to eliminate pathogens. Natural antimicrobials are normally not stable over time; microencapsulation and the use of edible coatings can improve stability of antimicrobial formulations and prolong their bioactivity. Phytosanitary irradiation doses to control insects (50 to 400 Gy) are relatively low compared to doses for food safety and sterilization applications. Lowering doses further could save money on treatment costs by reducing treatment time, increasing the capacity of irradiation facilities, and reducing any problems with commodity quality. Combining irradiation with other insect disinfestation modalities such as cold, heat, fumigation, modified atmospheres, and chemical insecticides is a possible means to reduce the radiation dose, and the duration, level, or concentration of the companion treatment while meeting the technical objectives of the quarantine treatment. Irradiation in combination with cold is particularly promising, as it may be a means to reduce the duration and therefore costs of current cold treatment protocols. Irradiation may also allow use of higher cold temperatures that do not cause chilling injury in cold-sensitive fruits. Directions for future research: The efficacy of active edible coating and active biodegradable packaging in combination with irradiation for microbial control needs further investigation and should be demonstrated at the industrial level. The use of combined treatments to eliminate viruses and parasites in food is not well studied and should be investigated. The effects of mild heat treatment before irradiation on insect radiotolerance and bacteria radiosensitization should be investigated. The relationship between MAP packaging and insect radiation tolerance needs to be explored for a wider variety of quarantine pest species, including surface pests and inherently tolerant Lepidoptera and mites. Additional research is needed to demonstrate the efficacy of irradiation plus cold combination treatments against insects in fresh produce while assessing commodity quality and the potential for commercial application.

Assessment of application of pectin, whey protein concentrate, soy protein isolated and methyl cellulose films to improve quality of potato strips

Deep-fat frying is a method widely used in the preparation of tasty food with an attractive appearance. However, oil uptake in fried foods has become a health concern. To meet the recent trends and consumer demand for lowfat products, there exists a need for reducing oil uptake during deep-fat frying. Recent studies have experimented with the use of edible coatings and films as barriers to the incorporation of oil during the frying process. Our objective was to evaluate the moisture retention and fat reduction capabilities of different edible film coatings (Methyl cellulose, Pectin, Whey protein isolate and Soy protein isolate) during deep-fat frying. Potato strips (size 0.8*0.8*8 cm) were used as the model food system. Oil uptake and moisture content were measured. Textural and colorific changes in fried potato strips were followed by the parameter maximum force (MF) and L*, a*, b*. What has emerged is that the using of edible coatings is an effective technique for reducing the oil contents and water retention of potato crisps. And also results showed that using of the coatings caused improving in texture and color qualities.

Conservação de mamão minimamente processado com uso de revestimento comestível à base de goma xantana

The objective of this study was to evaluate the preservation of papaya minimally processed by the use of edible coatings based on xanthan gum for 12 days at 4±1 °C. Different treatments were performed: control (T1) uncoated; 1 % glycerol and 0.5 % xanthan gum (T2); 1 % glycerol, 0.5 % xanthan gum and 1 % chitosan (T3); 1 % glycerol, 0.5 % xanthan gum and 0.25 % guar gum (T4); 1 % glycerol, 0.5 % xanthan gum, 0.25 % guar gum and 1 % chitosan (T5). Such coatings were prepared in aqueous solution and added to them 1% glycerol. In the control treatment and the coated pieces of papaya were analyzed weight loss, firmness, pH, titratable acidity, color, and microbiological groups: psychrophilic, Salmonella spp . , total coliform and thermotolerant. The different coatings based on xanthan gum were effective in preserving papaya minimally processed, relative to control sample. The addition of guar gum to xanthan coatings influenced negatively in the weight loss and the parameters of color, lightness, a* and b*. The addition of chitosan (T3) beneficially influence in reducing weight loss, maintenance of luminosity and a smaller reduction in parameters a* and b*, however, was not observed antimicrobial effect. Thus, it is suggested as an edible coatings papaya minimally processed coatings composed only xanthan gum (T2), which caused a reduction of weight loss, maintenance of lightness and b* and smaller reduction in a*. However, experiments aimed at maintaining firmness, pH and acidity should be conducted in future.

Xanthan Gum as a Carrier of Preservative Agents and Calcium Chloride Applied on Fresh‐Cut Apple

AbstractThis study aimed to evaluate xanthan gum as a carrier of preservative solution and calcium chloride in edible coating applied to fresh‐cut apple. The utilized coatings, prepared in aqueous solution, were: (T1) control, (T2) 1% glycerol, (T3) 1% glycerol and 0.5% xanthan gum, (T4) 1% glycerol, 0.5% xanthan gum and 1% CaCl2 (T5) 1% CaCl2 (T6) 1% ascorbic acid and 0.25% citric acid, (T7) 1% glycerol, 0.5% xanthan gum, 1% ascorbic acid and 0.25% citric acid (T8) 1% glycerol, 0.5% xanthan gum, 1% CaCl2, 1% ascorbic acid and 0.25% citric acid. The T8 treatment presented the best combination of results, with reduction of mass loss and oxidative browning, increase of firmness, lower growth of psychrotrophic microorganisms, molds and yeasts, and absence of total and thermotolerant coliforms, Escherichia coli and Salmonella sp.Practical ApplicationsFresh‐cut apples are appreciated worldwide for their flavor and nutritional composition. However, their shelf life is limited by changes in color, texture, appearance and microbial growth. An alternative to try to minimize the losses and increase the shelf life of this product is the use of edible coatings, maintaining the quality parameters of fresh fruit. Xanthan gum, a thickening agent, can be used as a carrier of preservative solution (citric and ascorbic acid) and calcium chloride to be used in edible coating in fresh‐cut apples. It can be considered useful to the minimal processing industry and used as an alternative to fast food and other ready‐to‐eat products, attending the demand for healthy and convenient foodstuffs.

Effects of Different Edible Coatings in Physical, Chemical and Microbiological Characteristics of Minimally Processed Peaches (Prunus persicaL. Batsch)

AbstractThe present work aimed at evaluating the effects of tara gum, xanthan and sodium alginate as edible coatings in physical, chemical and microbiological characteristics of minimally processed peaches. Peaches from Granada cultivar were peeled, cut into cubes and immersed in the solutions with the respective treatment. Four treatments were used. The minimally processed peaches were packed in PET packaging and stored at 4 ± 1C for 12 days. Physical and physicochemical analyses were performed, including mass loss, firmness (N), color (L*, a*, b* and Hue angle), pH, soluble solids (°Brix), and microbiological evaluations of psychotrophic microorganisms and mold and yeast. The treatment with tara gum associated to citric and ascorbic acids and sodium chloride presented the best results. Tara gum allowed a reduction of mass loss, firmness maintenance, lower color alteration and lower growth of molds and yeasts. Therefore, this gum presents potential for application as edible coating.Practical ApplicationsFresh‐cut peaches are appreciated worldwide for their exotic flavor and nutritional composition. However, their shelf life is limited by changes in color, texture, appearance and microbial growth. An alternative to try to minimize the losses and increase the shelf life of this product is the use of edible coatings, maintaining the quality parameters of fresh fruit. Tara gum is a cheap gum that has not been used as coating on minimally processed fruit, and in this work, this gum showed significant results in the quality of fresh‐cut peaches for a longer time. It can be considered useful to the minimal processing industry and used as an alternative to fast food and other ready‐to‐eat products, attending the demand for healthy and convenient foodstuffs.

Coberturas e Filmes Comestíveis Aditivados de Compostos Bioativos para Conservação de Frutas

Edible films and coatings have been applied on fruit to reduce aromatic compounds and texture loss and to increase the barrier to transport of fats and solutes. Furthermore, the surface layer on theproduct can protect the fruit crating a modified atmosphere that by controls the O2 and CO2 exchange, reducing respiration rate, metabolism and, consequently, the senescence. A new potential application of this technology is the use of edible coatings and films as carriers of diverse food additives such as antioxidants and antimicrobial agents. This review discusses the incorporation of functional ingredients into the edible coatings and films and highlights of the recent advance in the search for these incorporations. The future trends for the study area are also presented.

Atomizing Spray Systems for Application of Edible Coatings

Abstract: The use of edible coatings on fresh and processed food products as a means of extending shelf life by preventing or delaying spoilage, providing a partial barrier to moisture, oxygen, and carbon dioxide, improving the mechanical handling properties, and even as carriers of many functional ingredients, is rapidly growing. Edible coatings can be applied by different methods such as panning, fluidized bed, dipping, and spraying. This review presents and discusses some aspects of the application of edible coatings on food products using spraying, which is the most commonly used technique for applying food coatings and to obtain uniform layers.

Effects of Tapioca Starch/Decolorized Hsian-Tsao Leaf Gum-Based Active Coatings on the Quality of Minimally Processed Carrots

Edible coatings made from tapioca starch/decolorized hsian-tsao leaf gum (dHG) containing cinnamon essential oil or grape seed extract (GSE) were developed and applied to minimally processed carrots. Coatings based on 0.3% dHG and 1.7% tapioca starch were prepared and incorporated with 0.1–0.3% cinnamon oil or 0.3–0.6% GSE as antimicrobial agents. Fresh-cut carrots were immersed into coating solutions, placed in expanded polystyrene trays, and sealed in polypropylene bag. Changes in the initial respiration rate, the headspace atmosphere, color, microbial growth, and sensory evaluation were then measured. During refrigeration, the initial respiration rates for carrots with various coating treatments slightly increased as compared to the control group carrots, and the coatings with cinnamon oil showed the highest rates. Headspace analysis revealed that coated samples also had higher CO2 and lower O2 concentrations, which were consistent with the initial respiration rate results. Though samples coated with the antimicrobial solutions (cinnamon oil or GSE) did not show advantages in reducing microbial growth as compared to the control group carrots, they presented better acceptance during the sensory evaluations. The use of edible coatings successfully maintained the surface appearance and retarded the formation of “white blush” on the surface of carrots during refrigeration. While the visual appearance quality of minimally processed carrots was significantly improved by the coating treatments, the microbial growth was the same or even worse in some cases. Based on the pronounced improvements of the carrots’ appearance and the comparable microbial control, the plain starch/dHG coating without cinnamon oil or GSE was recommended for extending the shelf life of minimally processed carrots.

Effectiveness of Edible Coatings Combined with Mild Heat Shocks on Microbial Spoilage and Sensory Quality of Fresh Cut Broccoli (Brassica oleracea L.)

The use of edible coatings and mild heat shocks is proposed as postharvest treatments to prevent microbial deterioration of refrigerated broccoli. Minimally processed broccoli was coated with either chitosan or carboxymethyl-cellulose (CMC) combined or not with a previous application of a mild heat shock. The evolution of microbial populations (mesophilic, psycrotrophic, Enterobacteriaceae, molds and yeast, and lactic acid bacteria) was studied during 20 d of storage and fitted to Gompertz and logistic models. Results revealed that, at the end of the storage, chitosan coating significantly reduced all microbiological population counts, except lactic acid bacteria; while higher reduction was observed with chitosan coating combined with a heat shock treatment. A significant delay at the beginning of the exponential phase was observed for all the bacterial populations analyzed. On the other hand, CMC coating, with and without a previous thermal treatment, did not exert any antibacterial effect. Excellent agreement was found between experimental microbial counts and predicted values obtained from Gompertz and logistic models. Kinetic modeling was found to be valuable for prediction of microbiological shelf life of broccoli during storage. Results showed that the application of chitosan coating effectively maintained microbiological quality and extended shelf life of minimally processed broccoli. According to these results, the use of the edible chitosan coating alone or in combination with a heat mild shock appear to be a viable alternative for controlling microbiological growth and sensory attributes in minimally processed broccoli. The continuous consumer interest in high quality and food safety, combined with environmental concern has induced to the development and study of edible coatings that avoid the use of synthetic materials. The edible coatings, formed from generally recognized as safe materials, have the potential to reduce weight loss, respiration rate, and improve food appearance and integrity. It is one of the most effective methods to maintain food quality. On the other hand, heat treatments have been demonstrated to be effective as a nonchemical means of improving postharvest quality for a variety of horticultural products. The applications of mild heat shocks combined with edible coatings constitute an alternative for the natural preservation of crops for which the use of synthetic chemicals is objectionable.

Effect of Cassava Starch Coating on Quality and Shelf Life of Fresh‐Cut Pineapple (Ananas Comosus L. Merril cv “Pérola”)

This research studied the influence of treatment with ascorbic acid, citric acid, and calcium lactate dipping and cassava starch edible coatings on quality parameters and shelf life of fresh-cut pineapple in slices during 12 d at 5 °C. After previous tests, the treatments selected for this study were samples dipped into antibrowning solution with 0.5% of ascorbic acid and 1% of citric acid, with and without 2% of calcium lactate and coated with 2% of cassava starch suspensions. Changes in weight loss, juice leakage, mechanical properties (stress at failure), color parameters (L* and H*), ascorbic acid content, sensory acceptance, and microbial growth of fruits were evaluated. Samples only treated with antibrowning agents were used as control. Edible coatings with and without calcium lactate were efficient in reducing weight loss, juice leakage, and maintaining firmness during storage. However, these samples showed more browning and the ascorbic acid content was reduced. All treatments presented good sensory acceptance (scores above 6). The determining factor of shelf life of pineapple slices was the microbial spoilage. A shelf life of 8 d was obtained for pineapple slices only treated with antibrowning agents. On the other hand, coated samples showed a reduced shelf life of 7 d and higher yeast and mold growth. Thus, although cassava starch coatings were efficient in reducing respiration rate, weight loss, and juice leakage and maintained mechanical properties, these treatments were not able to increase the shelf life of minimally processed pineapple. Practical Application: Pineapple fruit is highly appreciated for its aroma, flavor, and juiciness, but its immediate consumption is difficult. Therefore, pineapple is a potential fruit for minimal processing. However, shelf life of fresh-cut pineapple is very limited by changes in color, texture, appearance, off-flavors, and microbial growth. The use of edible coatings as gas and water vapor barrier and antibrowning agents can extend the storage time and maintain the quality of fresh-cut produce. Cassava starch and alginate coatings are alternative to preserve minimally processed pineapples without changing the quality parameters of fresh fruit. Thus, this study is useful for consumers and fresh-cut industry interested in knowing factors affecting shelf life and quality of fresh-cut pineapple.

Effect of Edible Coatings, Storage Time and Maturity Stage on Overall Quality of Tomato Fruits

Problem statement: Tomato (Lycopersicon esculentum Mill.) is one of the most widely consumed fresh vegetables in the world; however, its highly perishable nature limits its postharvest life. Major losses in tomato quality and quantity occur between harvest and consumption. Therefore, the application of new technologies to extend the postharvest life of this commodity is needed. The use of edible coatings appears to be a good alternative. Approach: We evaluated the effect of carnauba and mineral oil coatings on the postharvest quality of tomato fruits (cv. “Grandela”). Stafresh 2505™ (carnauba) and Stafresh 151™ (mineral oil) coatings were applied on fresh tomatoes at two maturity stages (breaker and pink). The quality of tomatoes was evaluated periodically at 0, 5, 10, 15, 21 and 28 days of storage at 10°C, plus 2 days at 20°C. For respiration rate analysis, tomatoes were kept at 20°C for 16 days. Results: At the beginning of the study, CO2 production was reduced by 38 and 46% when applying the mineral oil coating on breaker and pink tomatoes, respectively. In addition, early during the study, the mineral oil coating showed suppression of ethylene biosynthesis at both maturity stages. Both coatings reduced 30% PG activity of tomato tissue. At the end of storage, mineral oil coatings delayed color changes and reduced weight losses for up 70 and 46% at the breaker and pink stages, respectively. Conclusion/Recommendations: Respiration rate, color, weight loss and enzyme activity were positively affected by mineral oil coating at both maturity stages. No effects on firmness, titratable acidity and pH were found by the coating application. We concluded that mineral oil coating could be a good alternative to preserve the quality and extend the postharvest life of tomato fruit.