Pre-harvest foliar application of mineral nutrients to retard chlorophyll degradation and preserve bio-active compounds in broccoli

Foliar application of micronutrients has become a common farm management practice to increase the overall yield of various crops. However, the effects of foliar fertilization on shelf life and postharvest quality of the crops are rather under-researched. The aim of this field experiment was to evaluate the effect of foliar application of individual mineral nutrients (calcium (Ca), zinc (Zn), manganese (Mn), and iron (Fe) on pre and postharvest quality of broccoli. The broccoli plants were subjected to single foliar sprays of either Ca, Fe, Zn, or Mn, which was repeated four times during plant growth at a 1 g/kg concentration. Once harvested, the broccoli heads were refrigerated at 4 °C for 28 days. Our results indicated that foliar application of Ca, Zn, Mn, and Fe did not have a significant effect on plant growth parameters, apart from enhancing Soil Plant Analysis Development (SPAD) chlorophyll meter values. However, during postharvest, foliar application treatment showed a positive response on weight loss during storage and reduction in yellowing of the broccoli heads. Foliar treatments increased the concentration of Nitrogen (N), Phosphorus (P), Ca, Zn, Mn and Fe significantly in the broccoli head tissue. Total chlorophyll content, total phenolic compound, ascorbic acid, peroxidase activity, glucoraphanin and glucobrassicin and flavonoids were significantly increased by all foliar treatments. Crude protein content and sulforaphane were enhanced by Ca and Mn treatments. Overall, foliar application of the investigated mineral nutrients may prove beneficial in improving the shelf-life and nutrient content of broccoli during postharvest handling and storage

Impact of salicylic acid, abscisic acid, and methyl jamonate on postharvest quality and bioactive compounds of cultivated strawberry fruit

BACKGROUND: Strawberry is one of the most highly consumed fruits worldwide. However, it is highly a perishable fruit postharvest. OBJECTIVE: To assess the effect of dipping strawberry fruits after harvest in plant growth regulators to maintain postharvest quality. METHODS: Treatments tested were: 2 and 4 mM salicylic acid (SA), 0.25 and 0.50 mM abscisic acid (ABA) and methyl jasmonate at 0.25 and 0.50 mM (MeJA). Bioactive compounds and fungal growth were assessed over 12 days of storage at 4°C. RESULTS: Both concentrations of SA and MeJA significantly suppressed weight loss, decay and respiration rate and 0.50 mM ABA also reduced decay. Both concentrations of SA retarded color development, and total soluble solids content was enhanced by 0.50 mM ABA and MeJA treatments. The most effective treatments for preserving firmness were 0.25 mM MeJA and 4 mM SA. Reduction in loss of ascorbic acid and bioactive compounds during storage was achieved using the highest concentrations of SA, ABA, and MeJA. Fungal growth was suppressed by all treatments but the best treatment was MeJA at both concentrations. CONCLUSIONS: All three plant growth regulators reduce postharvest changes in strawberry but effects differ amongst the treatments

Improving postharvest storage of fresh artichoke bottoms by an edible coating of Cordia myxa gum

This study aimed to prolong the shelf life of fresh-cut artichoke (Cynara scolymus L.) bottoms under refrigerated conditions (2 °C and 95 % RH) for a period of 9 d. Fresh artichoke bottoms were subjected to an edible coating of Cordia myxa gum (Cg) supplemented with or without calcium dichloride (CaCl2) 1 %, or ascorbic acid (AsA) 1 %. The key postharvest quality parameters which were investigated were weight loss, browning, polyphenol oxidase activity (PPO), firmness, vitamin C, and total phenolic compounds (TPC). Moreover, the microbial load of artichoke bottoms during the storage was also measured which comprised of total aerobic mesophilic and psychrotrophic bacteria, fungi, and E. coli. Results indicated that edible coating with Cg, when supplemented with CaCl2 or AsA, had a significant positive effect on weight loss, vitamin C, and TPC. Browning and PPO activities were significantly inhibited by Cg supplemented with AsA. The mesophilic and psychrotrophic bacterial count was significantly reduced in the presence of CaCl2 with or without Cg. For moulds and E. coli control, again Cg in combination with CaCl2 seems to be the most effective treatment. Hence, based on these findings, it can be recommended that postharvest coating Cg supplemented with CaCl2 could be a new application for delaying browning and extending the shelf-life of artichoke bottoms during refrigerated storage. Further research and development are required in commercial settings to test and scale the application of Cg in fresh-cut artichoke bottom industry

Postharvest exogenous melatonin treatment of strawberry reduces postharvest spoilage but affects components of the aroma profile

BACKGROUND: Strawberries are perishable fruits that decay quickly after harvest, but are valued for their distinctive taste and aroma. Melatonin is involved in plant resistance against stress, plant senescence and fruit ripening, and was shown to delay post-harvest spoilage of strawberries. OBJECTIVE: The effects of melatonin postharvest treatment on shelf-life and volatile organic compound profile were assessed in strawberry fruits cv “Luca”. METHODS: Strawberry fruit were treated with 100 μM melatonin and stored at 4°C for 12 days to assess whether melatonin treatment could delay spoilage without adversely affecting aroma. RESULTS: Melatonin treatment delayed fruit deterioration by reducing weight loss and incidence of decay as well as maintaining total soluble solids, titratable acidity, anthocyanin, and taste. Melatonin treatment also significantly reduced CO2 production compared to control fruits. The relative abundance of the majority of volatile organic compounds (VOCs) was not affected, however abundance of two VOCs that are important components of strawberry aroma were affected by melatonin treatment. CONCLUSIONS: Post-harvest treatment of strawberries with 100 μM melatonin improved strawberry quality and conserved bioactive compounds after 12 d of storage. However, components of the aroma profile were altered in a way which may affect consumer perception of quality

Phytochemical characterization and utilization of dried red beetroot (Beta vulgaris) peel extract in maintaining the quality of Nile Tilapia fish fillet

Phytochemicals derived from agro-industrial waste materials could be employed as functional food additives and natural antioxidants to replace their synthetic counterparts, which are increasingly being rejected. The current study aims to assess total phenolic compound (TPC), flavonoids, betalain contents, and antiradical scavenging using DPPH and IC50% of dried red beetroot peel (DRBP) extract at different concentrations of 50, 80, 100, 150, and 200 mg/100 mL t. In addition, a characterization of phenols and flavonoids was conducted using HPLC. The second part of this study aims to utilize aqueous DRBP extract in preserving Nile Talipia fish fillet at two concentrations of 80 and 100 mg/100 mL water, compared with 200 ppm of BHT (butylated hydroxytoluene) and control at 5 °C for 10 days. The DRBP aqueous extract was found to have a high concentration of TPC (832 mg/100 g), flavonoids (234 mg/100 g) and betalains (535 mg/100 g) compounds, resulting in a potential antioxidant activity. The IC50% for the extract was detected at 80 mg/100 mL extract. DRBP aqueous extract showed an excellent preservative effect on the fish fillet. Fish fillet samples treated with DRBP extract at a concentration of 100 mg/100 mL were superior in reducing TBA (thiobarbituric acid) increase compared with other treatments at the end of cold storage. Overall, the study showed that red beetroot extracts can act as a natural preservative agent due to their significant antioxidant activity, providing healthy and safe food to consumers

Extending the shelf-life of fresh-cut green bean pods by ethanol, ascorbic acid, and essential oils

Green beans are a perishable crop, which deteriorate rapidly after harvest, particularly when minimally processed into ready-to-eat fresh-cut green beans. This study investigated the effectiveness of ethanol, ascorbic acid (AsA), tea tree essential oil (TTO), and peppermint essential oil (PMO) on the quality and storability of fresh-cut green bean pods samples stored at 5 °C for 15 days. Our results indicated that samples treated with ethanol, AsA, TTO, and PMO preserved appearance, firmness (except ethanol), chlorophyll content, and moisture compared with the samples without any treatment (control). Additionally, higher vitamin C, total soluble solids (TSS), total sugars, and total phenolic compounds (TPC) were observed in samples treated with ethanol, AsA, TTO, and PMO compared with the control. The most effective treatments for controlling microbial growth were ethanol followed by either TTO or PMO. All the treatments had positive effects on shelf life, maintained quality, and reducing microbial growth during 15 days of cold storage. A particular treatment can be selected based on the economic feasibility and critical control point in the value chain

Improved shelf-life and consumer acceptance of fresh-cut and fried potato strips by an edible coating of garden cress seed mucilage

Coatings that reduce the fat content of fried food are an alternate option to reach both health concerns and consumer demand. Mucilage of garden cress (Lepidium sativum) seed extract (MSE) was modified into an edible coating with or without ascorbic acid (AA) to coat fresh-cut potato strips during cold storage (5 °C and 95% RH for 12 days) and subsequent frying. Physical attributes such as color, weight loss, and texture of potato strips coated with MSE solutions with or without AA showed that coatings efficiently delayed browning, reduced weight loss, and maintained the texture during cold storage. Moreover, MSE with AA provided the most favorable results in terms of reduction in oil uptake. In addition, the total microbial count was lower for MSE-coated samples when compared to the control during the cold storage. MSE coating also performed well on sensory attributes, showing no off flavors or color changes. As a result, the edible coating of garden cress mucilage could be a promising application for extending shelf-life and reducing the oil uptake of fresh-cut potato strips

Increasing the storability of fresh-cut Green beans by using chitosan as a carrier for tea tree and peppermint essential oils and ascorbic acid

The quality of fresh-cut green beans deteriorates rapidly in storage, which contributes to increased food waste and lower perceived customer value. However, chitosan (Cs) and certain plant essential oils show promise in reducing postharvest quality loss during storage. Here, the effect of Cs and the combinations of Cs + tea tree oil (TTO), Cs +x peppermint oil (PMO), and Cs + ascorbic acid (AsA) on the quality of fresh-cut green bean pods (FC-GB) is studied over a 15-d storage period at 5 °C. All four FC-GB treatments reduced weight loss and maintained firmness during storage when compared to uncoated FC-GB. Furthermore, all treatments showed higher total chlorophyll content, AsA, total phenolic compounds, and total sugars compared to the control. The best treatment for reducing microbial growth was a combination of Cs + AsA. Additionally, the combination of Cs with TTO, PMO, or AsA showed a significant reduction in the browning index and increased the antioxidant capacity of FC-GB up to 15 d postharvest

Irrigation with salt water affects growth, yield, fruit quality, storability and marker-gene expression in cherry tomato

The use of saline water for plant production will become increasingly necessary over future decades. In some cases, fruit quality such as in tomato, can be improved by irrigation with saline water. The influence of different salt concentrations on physiological responses and the expression of some selected genes of cherry tomato (Solanum lycopersicum L), cv. West Virginia 106, was examined. Tomato plants were grown in peatmoss substrate and irrigated with 0, 25, 50, 75, 100 or 150 mM sodium chloride (NaCl) in a glasshouse. The NaCl treatments of 75, 100 and 150 mM salt resulted in shorter plants, decreased stem width, a lower plant dry weight, fewer flowers, and smaller leaf area, while yield was reduced by treatment with concentrations of 50 mM NaCl and above. Average fruit weight and fruit number were also negatively affected by treatment with 50 mM salt and above. Salinity treatment led to increased fruit total soluble solids, titratable acidity and firmness and improved the taste index. Salt-responsive marker genes identified in Moneymaker were also induced in cherry tomato but not at the highest salt concentrations. Our results indicated that cherry tomato treated with 25 mM NaCl produced fruit with improved quality in comparison with non-salinized control plants without compromising yield, while at 50 and 75 mM the improved fruit quality was accompanied by a reduction in yield