Water Dip Research Articles

Impact of postharvest dips with abscisic acid, prohexadione, calcium, or water on bitter pit incidence and apple physiology

Bitter pit causes significant losses to apple producers, packers, and retailers each year. While bitter pit is often associated with calcium deficiency, this postharvest disorder is still not fully understood. Some studies have demonstrated positive effects of preharvest sprays with prohexadione and abscisic acid. To evaluate the effects of these phytohormones as postharvest dips, ‘Granny Smith’ apples were dipped after harvest in prohexadione-Ca, abscisic acid, or CaCl2. Undipped and water dipped fruit were included as controls. Bitter pit incidence and severity were evaluated on fruit stored at 0 °C and >90 % RH for 68–75 d. Postharvest prohexadione-Ca and abscisic acid treatments did not reduce bitter pit incidence over two years of testing. However, there was an increase in bitter pit incidence in control fruit dipped in water and surfactant compared to undipped control fruit in the first year of testing. This increase (7.5–14 %) was observed again in water dipped control fruit in each of the following 2 years of experimentation. Inclusion of 1 % calcium chloride in the dip solution eliminated this increase in bitter pit incidence. Applying calcium with a surfactant increased the apoplastic calcium concentration and reduced bitter pit development compared to water dipped fruit. Results indicate that the increase in bitter pit induced by water dips may be due to removal of residual calcium on the fruit’s surface from preharvest calcium treatments. Ethylene production was higher in bitter pit fruit compared to healthy fruit. Reduced and total ascorbate were decreased in pitted fruit compared to healthy calcium dipped fruit. Dichlorofluoresceine diacetate fluorescence was higher in tissue adjacent to pits compared to healthy tissue from healthy fruit, indicating accumulation of reactive oxygen species. However, no consistent trend was observed in antioxidant enzyme activity. These results indicate that bitter pit shares some, but not all, of the oxidative metabolic trends observed in other fruit calcium deficiency disorders.

Eco-safe hot water dip alleviates antioxidant level and sensory quality of Indian jujube fruits

Indian jujube (Ber) is highly perishable climacteric fruit owing to high decay index limiting its marketability and demands interventions to prolong shelf life. Fungicides are normally used to control rot during postharvest storage, however, residues left necessitate eco-safe alternatives like hot water dipping. Mature, pre-climacteric jujubes were dipped in 45, 50 or 55 °C water for 8, 6 or 4 min, respectively and then stored at 5 °C for periodic quality evaluation. Dipping fruits in 55 °C water resulted in 32.69 and 35.27, 64.21 and 58.57, 30.41 and 30.42, 38.50 and 52.20 % lower weight loss, decay index, malondialdehyde (MDA) and electrolyte leakage, whereas 15.40 and 16.77, 19.51 and 20.48 % greater antioxidant activity and ascorbic acid respectively for Umran and Pakwhite compared to 25 °C water dip. The highest glucose, fructose, malic, citric, and tartaric acids were 23.44 ± 1.04 and 29.9 ± 0.95, 30.68 ± 1.72 and 41.17 ± 2.34 mg/100 g, 138.1 ± 6.45 and 112.97 ± 6.16, 57.49 ± 1.71 and 53.78 ± 1.90, 79.58 ± 5.1 and 65.3 ± 4.83 μg/100 g whereas lower sucrose 12.34 ± 0.94 and 16.33 ± 1.05 mg/100 g were respectively recorded in 55 °C water dipped Umran and Pakwhite fruits. High dip water temperature (55 °C) exhibited better quality with the lowest decay index and weight loss, greater membrane integrity, bioactives content and sensory acceptance scores. Hence, hot water dipping was shown to be an effective residue-free option to extend the marketable period of jujubes to capture distant markets.

Effect of plant growth regulators on vegetative and floral of gladiolus (Gladiolus hybrid L. ) cv. Pusakiran

A experiment was carried out on the Effect of Plant Growth Regulators on the Vegetative and Floral of Gladiolus (Gladiolus hybrid L. ) cv. PusaKiran at Horticulture farm, Department of Horticulture, School of Agricultural Sciences, Dabok, Udaipur from October 2022 to February 2023, The experiment was laid out in Randomized Block Design. Replicated thrice with 10 treatment combinations, comprising three plant growth regulators with 3 levels T1-GA3 100 ppm, T2-GA3 150 ppm, T3-GA3 200 ppm, T4-NAA 100 ppm, T5-NAA 150 ppm, T6-NAA 200 ppm, T7-CCC 200 ppm, T8-CCC 400 ppm, T9-CCC 600 ppm, T10-Control (water dipping) for corm dipping for 24hours. The maximum plant height was observed in treatmentT3-GA3 200 ppm (94.40 cm),Among the treatments, T3- GA3 200 ppm recorded a greater number of leaves per plant (9.90), the days to spike emergence was a significant difference on days to spike emergence. Among the treatments, the earliest days to first floret show color was observed in treatment T4-NAA 100 ppm (90.40). Days to last floret show color was a significant difference on days to last floret show color. Among the treatments.Among the treatments, maximum spike length was observed in treatment T3-GA3 200 ppm (88.20 cm). T3-GA3 200 ppm (73.80) corm dip planting recorded the highest rachis length.

Optimization of Starch-Tannin Adhesives for Solid Wood Gluing.

Bio-based solutions for solid timber gluing have always been a very sensitive topic in wood technology. In this work, we optimize the gluing conditions of a starch-tannin formulation, which allows high performance in dry conditions and resistance to water dipping for 3 h, allowing for the D2 classification to be reached according to EN 204. It was observed that the starch-tannin formulations enhanced their performance by increasing the heating temperature, achieving satisfactory results at 140 °C for 13 min. The proportion of polyphenols in the mixture enhances the water resistance but is only tolerated until 20-30%. In particular, the addition of 10% tannin-hexamine enhances the water-resistant properties of starch for both quebracho and chestnut extract. The application of the jet of cold atmospheric plasma allows for good results with more viscous formulations, increasing their penetration in wood. Solid-state 13C-NMR analysis was also performed, and the spectroscopic information suggests establishing a coordination complex between starch and tannin.

Insecticides chlorantraniliprole and flubendiamide in Aster scaber: Dissipation kinetics, processing effects, and risk assessment

The residue characteristics, processing effects of washing and drying, and dietary risks of chlorantraniliprole (CAP) and flubendiamide (FBD) to Koreans were investigated using Aster scaber in a greenhouse. Following foliar application, the initial FBD residues were 3–10 times higher than those of CAP. However, the biological half-lives were similar at 6.0–8.3 and 6.8–9.9 days for CAP and FBD, respectively. The pre-harvest residue limits (PHRLs) 7 days before harvest, derived from the dissipation rates and maximum residue limits, were 12.2 and 33.2 mg/kg for CAP and FBD, respectively. For the removal of CAP and FBD from A. scaber, washing with a neutral detergent was more effective than running under or dipping in tap water (86.5 % and 66.2 %, respectively). Processing factors in fields I and II were 2.6 and 5.1 for CAP and 2.0 and 5.7 for FBD, respectively. Drying removal efficiencies in fields I and II averaged 46.4 % and 52.3 % for CAP and 48.4 % and 49.2 % for FBD, respectively. Chronic health risk assessments indicated that dietary exposure to CAP and FBD is acceptable for Korean health.

The optimization and energy efficiency analysis of a multi-tank solar-assisted air source heat pump water heating system

This article undertakes an optimization study of a solar-assisted air source heat pump water heating system by harnessing the advantages inherent in a multiple water tank arrangement. The Hooke-Jeeves algorithm was adopted to optimize the system parameters. The optimization variables encompass pivotal parameters such as water tank volume, collector area, dip angle, azimuth angle and heat pump power, while the objective function is the annual value of life cycle cost. By research and analysis of the monthly power consumption, electricity cost, solar fraction, average coefficient of performance (COP) and annual value of carbon emissions of the single-tank, dual-tank, and triple-tank system, it is discovered that the triple-tank system exhibits superior performance in overall aspects. Compared to the pre-optimized version, it achieves an annual energy consumption reduction of approximately 3.9%, leading to a 22.5% decrease in electricity expenses. Furthermore, it brings a 5.2% reduction in the annual lifecycle cost and a 6.3% decrease in carbon emissions, while simultaneously improving exergy efficiency by 4.8%.

Pharmacognostical specification of Cannabis sativa L. (Bhanga) leaves processed with various Ayurveda-recommended methods

Abstract BACKGROUND: Since years, Cannabis sativa L. has been used for medicinal, recreational, and spiritual purposes. Cannabinoids, mainly tetrahydrocannabinol (THC), possess great therapeutic potential; at the counterpart imparts psychotropic and euphoric effects. Considering therapeutic benefits, many countries are legalizing the cultivation and medicinal utilization of Cannabis species. Ayurveda science has recommended four methods for Cannabis processing to reduce its intoxicant effect. The pharmacognostical changes after processing of Cannabis leaves have been reported in this article. METHODS: The dry sample of female species of C. sativa L. was procured from Haridwar, Uttarakhand, India; after permission of the excise department. The samples have been tested microscopically for species confirmation. It has been processed by four different methods, namely Jalanimajjana (water dipping), Jalaprakshalana (water-wash), Godugdha Swedana (boiling in cow’s milk), and Babbul-twak Kwatha Swedana (boiling in the decoction of Acacia arabica (Lam.) Willd. Processed samples were tested for organoleptic characters, powder microscopic features and comparative analysis was done with unprocessed samples. RESULTS: Processing changes organoleptic characters and alters the morpho-anatomic features like reduction in trichomes; deformation of structures like cystolith, epidermis, fibers, spiral vessel, trichomes and oil globules. CONCLUSION: Processing changes organoleptic characters, deforms features like epidermis, parenchyma, sclerenchyma, stomata, spiral vessels, fibers, oil globules etc. and alters characteristics of trichomes which are suggestive of changes in active constituents like THC, CBD etc. Reduction in trichomes is indicative of fall in THC levels, which will help to reduce psychoactive nature of Cannabis.

Controlling Dielectric Film Defects to Increase the Breakdown Voltage of Conductive Polymer Solid Capacitors.

Aluminum solid polymer capacitors are promising devices for the increased demand for power electronics applications. Nonetheless, the low breakdown voltage of commercially available catalysts (∼100 V) limits their applications. In this study, a hydroxide-film-covered high-purity aluminum was anodized at 700 V in boric acid at 85 °C, and the effect of a second hot water immersion (posthydration treatment) after anodizing on the breakdown voltage was studied as a possible future treatment to enhance the withstand voltages of solid electrolytic capacitors. The dielectric breakdown voltage of the anodized aluminum with a PEDOT:PSS coating was ∼500 V, being ∼200 V less than the anodizing voltage; however, the dielectric breakdown voltage was increased above 700 V by introducing the posthydration treatment due to the formation of a nanovoid layer above the dielectric alumina film. Our research suggests that the highly dispersed nanovoids incorporated with PEDOT:PSS avoid the current concentration at some local regions, effectively increasing the dielectric breakdown voltage. The posthydration treatment increased the leakage current by introducing physical defects in the dielectric film. However, the leakage current was reduced by a voltage sweep below the breakdown voltage after the PEDOT:PSS coating or a second anodizing process before the coating, keeping the breakdown voltage above 600 V. A promising processing route to obtain aluminum solid capacitors with high withstand voltage (600 V) found in our research is, first, dipping in hot water; second, anodizing at 700 V; then a second hot water treatment; and a second anodizing at 400 V, which keeps the capacitance invariable with a breakdown voltage enhanced.

Intermittent Exothermic and Self-Healing Hydrated Salt Gels for Advanced Thermal Management of Underfloor Radiant Heating System.

Phase change materials (PCMs) have great prospects in thermal management applications because they can store and release latent heat. However, they are not suitable for on-demand heating as they can only release heat once. Herein, this work reports the intermittent exothermic of PCMs based on a supersaturated salt solution, exhibiting fully controlled long-term storage of energy, releasing and suspending heat on demand. Due to the high energy barrier, it is difficult for the supersaturated salt solution to nucleate; thus, it can store energy for a long time. Contact with seeds or other foreign objects can destroy the metastable state of the supersaturated salt solution and promote the formation of crystal nuclei, enabling crystallization and heat release on demand. The release of crystallization heat can be interrupted using scissors dip in water. Additionally, self-healing behavior allows it to be recycled and last longer, due to the presence of Fe3+ , inducing strong dynamic reversible non-covalent crosslinking through metal coordination bonds. Furthermore, the hydrated salts gels are applied for thermal management of underfloor radiant heating system, demonstrating four types of intermittent exotherms sequences amazingly. Further, the intermittent exothermic hydrated salts gels provide a more user-friendly thermal management of underfloor radiant heating systems.

Impact of Hot Water Pre-Treatments on the Drying Efficiency and Quality of Dates cv. Medjool

Dates are considered high energy nutritional fruits as they are packed with plenty of minerals, vitamins and sugars. Among various options available for processing and value addition, dry dates are one of the best possible alternatives to convert doka/khalal stage fruit into a high value product. However, the technology for their production is limited to a few traditional date growing countries and research is limited in the countries with expanding areas. Thus, the protocol for development of dry dates was standardised and the effect of different blanching intervals (5, 10 and 15 min) on the drying and quality parameters were studied. The rate of drying, dehydration ratio and rehydration ratio were found to increase with increasing hot water dipping durations while a 10 min hot water dip was found to be best for retaining the best sensory parameters of taste, colour/appearance and flavour. The total colour difference (ΔE) was also maximal (71.10) in the date fruits exposed to a 10 min dip treatment. The reducing sugars decreased and non-reducing sugars increased with increasing hot water dipping periods while there was no significant variation in the total sugar content of the treated dates. The tannins responsible for acrid taste were also reduced to a minimum (1.43%) compared to control (2.52%) fruits. Thus, the fruits of date cv. Medjool being bulky and fibrous with more dry matter content are well suited for dry date preparation.

Assessment and characterization of postharvest handling techniques in the value chain of Malay apple (Syzygium malaccense [L.] Merr. & L.M. Perry) in the Mount Cameroon region

The study examined the problem of excessive postharvest losses (PHLs) of Malay apples due to inadequate postharvest handling, which is hindering the growing demand for the fruit. The study surveyed 160 growers and 40 traders using semi-structured questionnaires to assess postharvest handling practices and propose storage techniques in the Mount Cameroon Region. Data were obtained via face-to-face interviews using semi-structured questionnaires. The data were analysed using descriptive and inferential statistics. Also, the effects of control (no application), hot water dip, 1-MCP, and Aloe vera gel treatments on the quality of Malay apples stored at room temperature for 24 days were examined using a completely randomised design. Chi-square results showed a significant (p< 0.05) association between sociodemographic factors [gender (χ2 = 25.004, p = 0.050), educational level (χ2 = 63.797, p = 0.034), and farming experience (χ2 = 48.87, p = 0.047)] and PHLs. Results showed that inadequate postharvest handling was leading to excessive PHLs, and appropriate postharvest techniques were necessary to maintain the fruit's quality and reduce losses. Significant differences were observed among harvesting, transportation and storage methods, packaging materials, and marketing methods, with harvest and storage showing higher PHLs of 40% and 35%, respectively. The study also found that 1-MCP and Aloe vera were effective in extending the storage life of Malay apples while maintaining quality. The study concluded that growers and traders should adopt proper postharvest techniques in their operations, including handpicking, and application of 1-MCP or Aloe vera gel coating to reduce PHLs and maintain fruit quality for 12 days. Overall, the study highlights the importance of better postharvest handling practices and storage techniques to reduce postharvest losses and improve the supply chain's efficiency. Future research could explore the applicability of these findings on other fruits and geographical locations, and investigate the underlying mechanisms that contribute to the effectiveness of these treatments.

Application of antioxidants and hot water treatments to improve shelf life of fresh-cut eggplants (Solanum melongena L.) during storage

The objective of this study was to evaluate the effect of antioxidant treatments on the conservation of cut eggplants (Solanum melongena L.), which was carried out in two stages. Initially, the effect of citric acid (CA), ascorbic acid (AA) and cysteine (Cys) solution at 0.5 and 1% on sensory attributes (general appearance and browning), and color parameters during storage were evaluated. Immersion in 1% AA was considered the best antioxidant since it maintained visual quality for 6 days. Subsequently, hot water dipping (HWD) treatments followed by the 1% AA solution were evaluated and optimized through the Response Surface Methodology (RSM). Sensory attributes, color parameters, respiration rate (RR), phenolic compounds (PhC), antioxidant capacity, as well as the activity of polyphenol oxidase (PPO) and peroxidase (POD) were assessed during cold storage. The results showed that HWD at 50 °C, 60 s and 1% AA was the optimal combination to control enzymatic browning and extend its fresh quality for up to 8 days. Furthermore, that combination of treatments reduced the PPO and POD activities and increased the PhC compared to the control (untreated), not finding significant differences between them in antioxidant capacity and RR. Therefore, the application of this combination would be the most appropriate to preserve the quality of the fresh-cut eggplants for 8 days of storage at 4 °C.

The effects of processing aids and techniques on olive oil extractability and oil quality índices

This study was conducted to investigate the effects of processing aids and techniques such as talcum powder (2% w/w), calcium carbonate (2% w/w), warm water dipping (45 °C), combined treatment (warm water dipping+2% calcium carbonate) and control (without adding processing aid) on extractability and quality of ‘Tarom 7’ olive oil as randomized complete block design with three replicates. The results showed that there were no significant differences in the carotenoid content, K232, fatty acid profile or the Cox’s value in the oil obtained from untreated and treated fruits with processing aids. The highest chlorophyll content (0.84 mg/kg), total phenolic content (236.94 mg/kg), paste extractability (8.5%) and the lowest peroxide values (0.32 meqO2/kg), K270 (0.38) were obtained from the oil extracted with 2% talc powder. According to the results, it can be suggested that the 2% talc powder treatment could have a positive effect on olive oil quality and paste extractability.

Organoleptic characteristics evaluation of Diab mango fruits as affected by hot water treatments

Due to its rapid ripening after harvest, mango is a perishable fruit with a short shelf life. Organoleptic parameters such as color, flavor, texture and aroma are factors critical to consumer acceptance and the success of the fresh produce. Hot water treatments (HW) technology is gaining popularity worldwide for its potential to extend the shelf life of mango fresh produce with better fruit quality. The present study was conducted at the two successive seasons of 2019 and 2020 to evaluate the hot water dipping (HWD) treatments at 45 or 50oC for 5 and 10 min., and then stored at 8oC±2oC and 90-95% relative humidity as shipping simulation for 3 weeks and then ripened at 20oC too. The sensory characteristics score of mango fruits were measured by panelists who utilized the Hedonic test in evaluating the quality scores samples. Our results at the end of ripening storage duration (21days) appeared that the HW treatment at 50oC for 10 min showed the highest significant firm, texture, and pulp color score (3.49, 3.00 and 5.00) of mango fruits compared with untreated with lower score (1.15, 2.00 and 4.67). Moreover, the sensory score as aroma and flavor cleared gradually and showed the same trend, recording the best aroma and mango flavour score (4.67, 3.67). At the same time, control fruits have the lowest taste score (3.00 and 2.33).

Efficacy of combined caprylic acid and thymol treatments for inactivation of Listeria monocytogenes on enoki mushrooms in household and food-service establishments

Raw enoki mushroom is a high-risk vector for listeriosis, which led to foodborne outbreaks resulting in four deaths in the United States in 2020. This study aimed to investigate the washing method for the inactivation of L. monocytogenes in enoki mushrooms for household and food service establishments. Five methods of washing fresh agricultural products without using disinfectants were selected: (1) rinsing under running water (2 L/min, 10 min), (2–3) dipping in water (200 ml/20 g) at 22 or 40 °C for 10 min, and using (4) 10% NaCl or (5) 5% vinegar at 22 °C for 10 min. The antibacterial efficacy of each washing method along with the final rinse was tested with enoki mushrooms inoculated with a 3-strain cocktail of L. monocytogenes (ATCC 19111, 19115, 19117; ca. 6 log CFU/g). The 5% vinegar showed a significant difference in antibacterial effect compared to the other treatments except 10% NaCl (P < 0.05), with the maximum elimination of L. monocytogenes by 1.23 log CFU/g. Therefore, a disinfectant for enoki mushrooms that can complement the commonly used washing method was developed using antimicrobials (caprylic acid, CA: 0, 0.20, 0.40%; thymol, TM: 0, 0.075, 0.15%). By combined treatment of 0.40% CA and 0.15% TM at 22 °C for 10 min, L. monocytogenes was completely inactivated (>5.55 log reduction CFU/g) and did not recover after enrichment, although individual treatments of antimicrobials showed low bactericidal effects of <1.50 log reduction CFU/g. The bacterial membrane disintegration induced by the disinfectant was analyzed through flow cytometry. Additionally, the sensory scores (odor and appearance) and color parameters (L*, a*, and b*) of enoki mushrooms treated with the disinfectant were not significantly different from those of enoki mushrooms washed with water (P > 0.05). Our findings suggest a washing disinfectant consisting of low concentrations of CA and TM with synergistic antibacterial effects without quality deterioration that can ensure the safe consumption of raw enoki mushrooms in homes and food service establishments.

Postharvest Application of Potato Starch Edible Coatings with Sodium Benzoate to Reduce Sour Rot and Preserve Mandarin Fruit Quality

Starch is a biodegradable polymeric carbohydrate that can easily form films and coatings and can readily be obtained from some food industry by-products and wastes, which may contribute to the circular bioeconomy. In this work, we studied the potential of two edible coating emulsions based on pregelatinized potato starch (PPS) and glyceryl monostearate (GMS) alone (F6 and F10) or formulated with the food additive sodium benzoate (SB, 2%) (F6/SB and F10/SB) to control sour rot, an important citrus postharvest disease caused by the fungus Geotrichum citri-aurantii, and maintain postharvest quality of cold-stored ‘Orri’ mandarins. The PPS-GMS coating application was compared to dipping in water (uncoated controls) and dipping in a 2% SB (w/v) aqueous solution. The results showed that the coating F10/SB was the most promising treatment to control sour rot on mandarins, with reductions in disease incidence with respect to the uncoated control samples of 94, 69, and 55% after 2, 4, and 6 weeks of storage at 5 °C, respectively. Coatings formulated without SB were ineffective. Regarding fruit quality, the coating F10 was the most effective to reduce weight loss, maintain firmness, and provide gloss on mandarins stored at 5 °C for up to 6 weeks followed by a shelf-life period of 1 week at 20 °C. The addition of SB to the PPS-GMS coatings adversely affected these coating properties, but the coating F10/SB still reduced weight loss compared to uncoated controls without negatively affecting the fruit physicochemical (juice titratable acidity, soluble solids content, and volatiles content) and sensory quality (overall flavor, off-flavors, external aspect). Overall, the coating F10/SB showed the greatest potential for commercial use as an efficient and environmentally friendly alternative to conventional fungicides and waxes for sour rot control and quality preservation of cold-stored mandarins.

Standardization of dehydration techniques for vegetable type cluster bean (Cyamopsis tetragonoloba L.)

An experiment was conducted to standardized dehydration techniques for cluster bean (Cyamopsis tetragonoloba L.) pods at ICAR-CIAH, Bikaner during 2020-21. The pods were blanched for different durations (3, 4, 5, 6 and 7 minutes) in boiling water to standardize blanching process. Five minutes blanching in boiling water followed by immediate dipping in cold water was found optimum for getting quality dehydrated product. Blanching treatment significantly enhanced the drying (5.67) and rehydration rate (4.65) and augmented rehydration capacity of dried pods. The dehydration recovery was 21.24% of fresh pods. The dried samples stored with HDPE pouches had low moisture content and high rehydration capacity than the samples stored with LDPE pouches. Thus, it is recommended that blanching is an essential process for quality pods. The HDPE pouches were found suitable packaging material for storage stability of dried pods.

Effect of Post-Harvest Treatments on Quality Characteristics of Carrots During Storage

Background: Carrot due to its versatility in culinary uses is considered to be one of the most preferred vegetable. The carrot in Pakistan ranks third among winter vegetables, but due to adoption of improper postharvest techniques and storage, it leads to a great reduction in its quality.&#x0D; Objective: The study was carried out to assess the effect of different treatments on quality characteristics of carrot.&#x0D; Methodology: The study was carried out at the Laboratory of Farm Structures, Sindh Agriculture University Tandojam, Pakistan. Freshly harvested mature carrots free from damage and fungal attack were obtained from field. The carrot samples were subjected to different post-harvest treatments i.e. 40 ºC hot water dip for 2 minutes, 50 ºC hot water dip for 2 minutes, 0.4% concentration of calcium chloride (CaCl2) dip for 2 minutes and tap water.&#x0D; Results: The results revealed that moisture content and firmness decreased with increasing storage duration, whereas weight loss, fungal incidence and total soluble solids increased with increasing storage duration. The carrots treated with 0.4% concentration of CaCl2 dip for 2 minutes had maximum moisture content (78.32%) and firmness (4.12 lbs), with minimum weight loss (41.33%), fungal incidence (38.14%) and total soluble solids (10.43%), followed by 40 ºC hot water dip for 2 minutes, 50 ºC hot water dip for 2 minutes and tap water.&#x0D; Conclusion: The carrots treated with 0.4% concentration of CaCl2 dip for 2 minutes showed better quality characteristics at the end of storage. The adoption of this treatment should therefore be encouraged in the developing countries for extending the quality characteristics of carrots.

Attenuating sugar spot and retaining quality of banana fruits by combined use of hot water and calcium lactate during storage.

Combined use of hot water (HW) treatment and calcium lactate (CL) is a promising postharvest approach to preserve the food value and prolong the shelf life of fruits. The present experiment aims to determine the physiological loss in weight, firmness, respiration rate, ethylene and biochemical attributes of banana fruits treated with hot water (50 °C for 7 min) and aqueous CL dipping (1, 2, and 3% for 2 min). Treated fruits were stored under ambient conditions (22-25°C temperature and 60-65% of relative humidity) for up to 9 days. The study showed that combined use of HW and CL (3%) maintained higher hue angle, peel firmness (4.4 N), reduced decay loss (10.63%), respiration and ethylene evolution rate of stored fruits. Also, CL treatments (3%) with HW proved the best which reduced 6-fold sugar spot and 1.5-fold decay loss over untreated fruits. At the end of storage sensory parameters such as mouthfeel, peel colour and overall acceptability (score 6.9) were recorded higher in HW and CL 3% treated fruits. The findings indicated that pre-storage combined use of HW and CL has a great potential to preserve quality, delay ripening, and reduce sugar spots, and postharvest decay loss in banana fruit without any adverse effect on consumer appeal.

Control of banana anthracnose by hot water dip: A semi-empirical model coupling heat transfer and Colletotrichum musae inactivation

A semi-empirical model was developed to predict simultaneously time-temperature distribution inside the unripe banana and fungal reduction during the hot water dip, in order to simulate different process conditions for controlling banana anthracnose disease. For this purpose, the kinetic parameters of Colletotrichum musae reduction were estimated based on the thermal death time concept (z = 3.56 °C and D50°C= 1044 s), and evaluated in different simulated media (unripe and fully ripe banana peel agar media). At the same time, a heat transfer model based on the Fourier equation was developed considering two unripe banana domains (peel and pulp). The comparison between the predicted and observed number of C. musae spores after the thermal treatment of unripe banana was satisfactory (coefficient of variation less than 10%), suggesting that the survival ratio is affected by the banana composition. The resulting model can be used to simulate different time-temperature scenarios, and to show how the parameter combinations may affect C. musae reduction in the unripe banana during the hot water dip process.