A loe Vera Gel and Honey-Based Edible Coatings Combined with Chemical Dip as a Safe Means for Quality Maintenance and Shelf Life Extension of Fresh-Cut Papaya

The Composition of Fatty Acids in Bee Pollen, Royal Jelly, Buckthorn Oil and Their Mixtures with Pollen Preserved for Storage

Honey produced by A. mellifera contains minor components present in the nectar collected from plants. Various studies of honey components and all other bee products can be informative in assessing their quality. The aim of the present study was to determine the content and composition of fatty acids (FAs) in sea buckthorn oil (SBO), royal jelly (RJ) and bee pollen (BP) and the changes in FAs content in these products during storage. The diversity of FAs and the effect of storage time on FAs content was also evaluated for the prepared-for-preservation mixtures, which included the following samples: pollen mixed with honey at a ratio of 1:2 (w/w); sample BPH, a well; BPH + 1% (w/w) SBO; and BPH + 1% (w/w) SBO + 2% (w/w) RJ. Fresh bee-collected pollen and RJ were stored at -20 °C, whereas the conserved samples were stored at +4 °C in hermetically sealed jars. The data revealed that RJ demonstrated the highest diversity of fatty acids compared to BP and BP prepared for storage with honey along with SBO and RJ. Palmitic and stearic acids were found in the highest amounts out of the eight saturated fatty acids identified in the studied SBO and RJ. The amount of these fatty acids in RJ compared to SBO was 1.27 and 6.14 times higher, respectively. In total, twenty-two unsaturated fatty acids (USFA) were identified in RJ and fourteen were found in SBO. The SBO used in this study was found to be high in linoleic acid, resulting in an increased n-6 fatty acids ratio in the prepared samples. Essential fatty acids eicosapentaenoic (EPA) and docosahexaenoic (DHA) were found in RJ, as well as in BP and BP mixed with honey. These FAs were not identified in the samples prepared with SBO even in the sample supplemented with RJ. The highest decrease in docosadienoic fatty acid was found in the BPH sample compared to BP, while arachidonic acid mostly decreased in BPH + 1% SBO compared to the BPH + 1% (w/w) SBO + 2% (w/w) RJ samples stored at +4 °C. Bee-collected pollen had the greatest influence on the number of FAs in its mixture with honey.

Preservation of Fresh-Cut 'Maradol' Papaya with Polymeric Nanocapsules of Lemon Essential Oil or Curcumin

Papaya is one of the most consumed fruits in the world; however, tissue damage caused by cuts quickly leads to its decay. Therefore, this study aimed to prepare and characterize lemon oil and curcumin nanocapsules to evaluate their capacity for preserving fresh-cut papaya. Lemon essential oil and curcumin nanocapsules were prepared using ethyl cellulose (EC) and poly-(ε-caprolactone) (PCL) by the emulsification-diffusion method coupled with ultrasound. The particles had sizes smaller than 120 nm, with polydispersity indices below 0.25 and zeta potentials exceeding -12 mV, as confirmed by scanning electron microscopy. The nanoparticles remained stable for 27 days, with sedimentation being the instability mechanism observed. These nanoparticles were employed to coat fresh-cut papaya, which was stored for 17 days. The results demonstrated their remarkable efficacy in reducing the respiration rate. Furthermore, nanocapsules maintained the pH and acidity levels of the papayas for an extended period. The lemon oil/EC nanocapsule treatment retained the color better. Additionally, all systems exhibited the ability to minimize texture loss associated with reduced pectin methylesterase activity. Finally, the nanocapsules showed a notable reduction in polyphenol oxidase activity correlating with preserving total phenolic compounds in the fruit. Therefore, the lemon oil and curcumin nanoparticles formed using EC and PCL demonstrated their effectiveness in preserving fresh-cut 'Maradol' papaya.

WITHDRAWN: Heavy metal ions and dyes removal from aqueous solution using Aloevera-based biosorbent: A systematic review

This article has been withdrawn: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been withdrawn at the request of the authors, editor and publisher. The publisher regrets that an error occurred which led to the premature publication of this paper. The publisher apologizes to the readers for this unfortunate erro

Food Handling Practices for Apple Drying in Home Kitchens in the United States: A Survey

ABSTRACT

Fruit drying has traditionally received little food safety attention in spite of Salmonella outbreaks and recalls involving low-moisture foods. This study was conducted to assess the food safety implications during the home drying process, with dried apples as an example. A cohort of home apple dryers (n = 979) participated in an online survey through Qualtrics XM in May 2021. The results showed that participants' knowledge of safe food handling practices regarding dried fruit was low. On average, participants used only 8 of 18 identified food safety practices during apple drying. The survey revealed inadequate frequency of hand washing during apple preparation, potential points of cross-contamination from kitchen tools, lack of hurdle technology without a pretreatment step, failure to incorporate a thermal kill step during drying, and a lack of objective measurements to ensure that target parameters are attained. Participants mainly pretreated apples for sensory improvement instead of microbial reduction. When presented with some benefits of pretreatment, participants who did not pretreat their apples considered doing so to kill bacteria. The use of safe food handling practices differed within demographic groups. Participants 18 to 39 years old (mean = 7.47; 95% confidence interval [CI] = 7.26, 7.67) and 40 to 59 years old (mean = 7.43; 95% CI = 7.16, 7.70) reported using fewer safe practices than did those >60 years old (mean = 8.49; 95% CI = 8.22, 8.75), and participants who identified as male (mean = 7.38; 95% CI = 7.16, 7.60) reported using fewer safe practices than did those identifying as female (mean = 7.92; 95% CI = 7.74, 8.11). The findings of this study provide food handling data to support the development of more accurate food safety risk assessment models and to guide the development of food safety education for consumers who dehydrate produce in the home.

HIGHLIGHTS

Pectin-Based Edible Coating Combined with Chemical Dips Containing Antimicrobials and Antibrowning Agents to Maintain Quality of Fresh-Cut Pears

The aim of this study was to assess the effects of pectin coating alone (PE) or combined with chemical dips containing potassium sorbate (PS) or sodium benzoate (SB) as antimicrobials, and N-acetyl cysteine (N-AC) or ascorbic acid (AA) + citric acid (CA) as antibrowning agents, on weight loss, color values, browning index, firmness, titratable acidity, soluble solids content, total phenolic content, antioxidant activity and sensory attributes of fresh-cut pears during 15-day storage at 8 °C. Pectin coating delayed weight loss and improved firmness of fresh-cut pears as compared to control samples. Addition of either 1% N-AC or 1% CA + 1% AA in the formulation of the chemical dip protected the phenolic compounds and enhanced the antioxidant activity of fresh-cut pears during storage. PE + 0.2% SB + 1% N-AC and PE + 0.2% PS + 1% N-AC were the most efficient treatments in preserving color and reducing the browning index of fresh-cut pears during 15-day storage at 8 °C and received the highest scores for all sensory attributes throughout 12 days of storage. The results demonstrate the feasibility of PE + 0.2% SB + 1% N-AC and PE + 0.2% PS + 1% N-AC for extending the shelf life of fresh-cut pears.

Aloe vera gel coating delays softening and maintains quality of stored persimmon (Diospyros kaki Thunb.) Fruits

The effect of Aloe vera (AV) gel coating was studied on antioxidant enzymes activities, oxidative stress, softening and associated quality attributes of persimmon fruits. The fruits were coated with 0 and 50% AV-gel coating and stored for 20 days at 20 ± 1 ºC. AV-gel coated fruits exhibited considerably less weight loss, hydrogen peroxide level, electrolyte leakage and malondialdehyde content. AV-gel coated fruits had significantly higher ascorbate peroxidase, peroxidase, superoxide dismutase and catalase activities. In addition, AV-gel coating suppressed pectin methylesterase, polygalacturonase and cellulase activities and showed higher ascorbic acid, DPPH scavenging antioxidants and phenolics, and lower sugars and carotenoids. To the best of our knowledge, these results are the first evidence that AV-gel coating modulates the activities of cell wall degrading enzymes to delay ripening in climacteric fruits. So, AV-gel coating prohibited the onset of senescence by activating enzymatic antioxidant system, accumulating bioactive compounds and suppressing cell wall degradation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05412-5.

Polyphenoloxidase (PPO): Effect, Current Determination and Inhibition Treatments in Fresh-Cut Produce

Fresh-cut produce are quite popular among consumers due to their eating ease, high quality and functional content. However, some of the processing steps taking place during minimal processing (such as cutting, peeling, draining, etc.) might speed up decay, e.g., microbial growth, dehydration or browning. When it comes to the latter, polyphenol oxidase (PPO) plays an important role, being the center of many works focused on the understanding of its reaction mechanism and the application of conservative techniques. The aim of this review study was to compare recent research about the effect of PPO on minimally processed fruits and vegetables, trying to understand the way it acts, the measurement of its activity and current treatments, such as modified atmosphere packaging, washing treatments or edible coatings, among others. In conclusion, the combination of conservation techniques (that is, hurdle technology) is vital to guarantee global quality in minimally processed fruits and vegetables, including synergistic effects which will allow the use of mild treatment conditions to decrease PPO activity. However, further research is required to clearly understand PPO inhibition in trendy techniques such as irradiation.

Controlling Fusarium oxysporum Tomato Fruit Rot under Tropical Condition Using Both Chitosan and Vanillin

Tomato Lycopersicon esculentum Mill. is one of the most cultivated and widely consumed vegetables in the world. However, it is very susceptible to the infection initiated by Fusariumoxysporum fruit rot, which shortens post-harvest life and thus reduces market value. This disease can be regulated appropriately by the application of synthetic fungicides. However, chemical fungicides constitute a serious health risk, and have harmful environment effects and increase disease resistance, even when microbes are dead. Hence, to overcome this problem, chitosan and vanillin, which have antimicrobial bioactive properties against the growth of microorganisms, could be an alternative to disease control, while maintaining fruit quality and prolonging shelf life. The aim of this research was to evaluate the antimicrobial activity of chitosan and vanillin towards the inoculate pathogen and to investigate the effect of chitosan and vanillin coating in vivo on Fusarium oxysporum fruit rot and defense-related enzymes (PAL, PPO and POD). Chitosan and vanillin in aqueous solutions, i.e., 0.5% chitosan + 10 mM vanillin, 1% chitosan + 10 mM vanillin, 1.5% chitosan + 10 mM vanillin, 0.5% chitosan + 15 mM vanillin, 1% chitosan + 15 mM vanillin and 1.5% chitosan + 15 mM vanillin, were used as edible coatings on tomatoes stored at 26 ± 2 °C and 60 ± 5 relative humidity. The result revealed 1.5% chitosan + 15 mM vanillin was able to control disease incidence by 70.84% and severity by 70%. These combinations of coatings were also able to retain phenylalanine ammonia-lyase (PAL), peroxidase activity (POD), and polyphenol oxidase (PPO) enzyme activities as well as prolong shelf life of tomatoes up to 15 days.

Browning metabolism and quality of fresh-cut drumstick (Moringa oleifera) as influenced by acidulant treatments

Though fresh-cut products save our time, but they are very much prone to enzymatic browning that drastically affects product's quality and marketability. Drumstick pods are considered as super food due to high nutritional contents. However, the fresh-cut pods are prone to brown discoloration. The enzyme activities promote the softening and cut-surface browning of pods, thus deteriorates their texture, decreases consumer appeal and shortens the shelf life. So, we aimed to assess the effect of citric (1%) and ascorbic (1%) acid treatments on quality attributes of fresh-cut drumsticks at 3-d interval during storage (5 ± 1 °C). In general there was an increase in lignin and quinone contents, while phenolic content was decreased during storage. However, samples subjected to ascorbic acid dip had higher phenolic content, lower rate of lignin formation, and reduced membrane permeability. Enzyme activities (polyphenol oxidase and peroxidase) were found to increase during storage, however, samples treated with ascorbic acid showed lower activities than that of the control and citric acid treated samples. The reduced enzyme activities resulted in the reduced browning incidence and maintained the quality. Therefore, postharvest dip of fresh-cut drumstick in to ascorbic acid (1%) could be suggested to increase the shelf life with reduced browning during low temperature storage.

Inhibitory effects of organic acids on polyphenol oxidase: From model systems to food systems

Organic acids are widely utilized in the food industry for inhibiting the activity of polyphenol oxidase (PPO) and enzymatic browning. This review discusses the mechanisms of inhibition of PPO and enzymatic browning by various organic acids based on studies in model systems, critically evaluates the relevance of such studies to real food systems and assesses the implication of the synergistic inhibitory effects of organic acids with other physicochemical processing techniques on product quality and safety. Organic acids inhibit the activity of PPO and enzymatic browning via different mechanisms and therefore the suitability of a particular organic acid depends on the structure and the catalytic properties of PPO and the physicochemical properties of the food matrix. Studies in model systems provide an invaluable insight into the inhibitory mechanisms of various organics acids. However, the difference in the effectiveness of PPO inhibitors between model systems and food systems and the lack of correlation between the degree of PPO inhibition based on in vitro assays and enzymatic browning imply that the effectiveness of organic acids can be accurately evaluated only via direct assessment of browning inhibition in a particular food system. Combination of organic acids with physical processing techniques is one of the most viable approaches for PPO inhibition since the observed synergistic effect helps to reduce the undesirable organoleptic quality changes from the use of excessive concentration of organic acids or intense physical processing.

Polysaccharide-based component and their relevance in edible film/coating: a review

Purpose

The purpose of this paper is to present an overview of functional properties of the polysaccharide-based component and their application in developing edible film and coating for the food processing sector.

Design/methodology/approach

In this review study, approximately 271 research and review articles focusing on studies related to polysaccharide-based components and their film-forming properties. This article also focused on the application of polysaccharide-based edible film in the food sector.

Findings

From the literature reviewed, polysaccharide components and components-based edible film/coating is the biodegradable and eco-friendly packaging of the materials and directly consumed by the consumer with food. It has been reported that the polysaccharide components have excellent properties such as being nontoxic, antioxidant, antimicrobial, antifungal and with good nutrients. The polysaccharide-based edible film has lipid and gas barrier properties with excellent transparency and mechanical strength. In various studies, researchers worked on the development of polysaccharide-based edible film and coating by incorporating plant based natural antioxidants. This was primarily done for obtaining improved physical and chemical properties of the edible film and coating. In future, the technology of developing polysaccharide-based edible film and coating could be used for extending the shelf life and preserving the quality of fruits and vegetables at a commercial level. There is more need to understand the role of edible packaging and sustainability in the food and environment sector.

Originality/value

Through this review paper, possible applications of polysaccharide-based components and their function property in the formation of the edible film and their effect on fruits, vegetables and other food products are discussed after detailed studies of literature from thesis and journal article.

Aloe vera waste biomass-based adsorbents for the removal of aquatic pollutants: A review

Aloe vera has been cultivated for many centuries for its beneficial properties, finding application in a wide range of medical and health products. Nowadays, the research has also focused on an alternative use of Aloe vera which is related to environmental applications such as clean water technology/wastewater treatment process. In recent years, biosorption has been shown to be a cost-effective and efficient alternative method for removing various pollutants from wastewater and water. This work provides a comprehensive review on using Aloe vera waste biomass-based sorbents, as well as modified counterparts, for the removal of heavy metals, dyes and other pollutants from aqueous media. The discussed biosorbents have been grouped in five categories based on the treatment of the Aloe vera leaves. Adsorption mechanisms, in addition to the significant factors influencing sorption capability like physical and chemical properties of the adsorbent, initial concentration, initial pH and temperature of the solution, dosage and contact time, have been discussed in detail. Furthermore, the applied equilibrium and kinetic models have been also summarized. The history, taxonomy, botany, and applications of Aloe vera are also presented in brief.