Effect Of Hot Water Treatment Research Articles

Postharvest Hot Water Treatment Followed by Chitosan- and κ-Carrageenan-Based Composite Coating Induces the Disease Resistance and Preserves the Quality in Dragon Fruit (Hylocereus undatus)

ABSTRACT : Postharvest diseases and loss of freshness are major problems that cause the deterioration of dragon fruit. The present study determined the effect of hot water treatment (HWT) at 50°C for 5 min followed by 1.0% chitosan and 0.2% κ-carrageenan-based composite coating to counter the issues. The results showed that HWT followed by the composite coating-enhanced antioxidant enzyme activities and reduced accumulation of H2O2 in the peel, which demonstrated the defensive response in the tissues leading to reduce disease development. The chitinase and β-1,3-glucanase did not show a significant effect in reducing the postharvest diseases of dragon fruit. While the HWT helped to increase phenolics content and antioxidant capacity in the pulp, the composite coating was crucial to maintain green color of the bract. Therefore, we concluded that HWT combined with composite coating controlled the diseases via antioxidant defensive response and maintained the overall quality of dragon fruit for 30 days of storage at 10°C.

Effect of hot water treatment on chilling injury and lignification of cold-stored fresh areca nut (Areca catechu L.).

Fresh areca nut is widely favored by consumers in South and Southeast Asia. However, postharvest areca nut perished quickly and was vulnerable to chilling injury (CI) and lignification during traditional cold storage. In order to alleviate this situation, hot water treatment was applied to investigate its effect on CI and lignification of fresh areca nut during cold storage at 13°C. Areca nuts were submersed in hot water at 45°C (HW45) and 50°C (HW50) for short-term 5min compared to fruit submersed in water at 20°C (CT), then stored at 13°C with 90% humidity for 60days. CI, malondialdehyde (MDA), electrolyte leakage (EL), lignin and total phenolic content, related enzymes including phenylalanine ammonia-lyase (PAL), cinnamyl alcohol dehydrogenase (CAD) and peroxidase activity (POD) were examined. Results indicated that two HW treatments both induced chilling tolerance and delayed lignification of areca nut to varying degrees during cold storage compared with the CT. Among which, HW45 treated-areca nuts had the lowest CI, MDA content and EL while maintaining the highest total phenolic content. Moreover, no significant effects were found between HW45 and HW50 on tissue lignification, but they both effectively blocked lignin accumulation by inhibiting PAL, CAD and POD activities compared with the CT. The present study provided a safe physical method to mitigate CI and delay tissue lignification in cold-stored areca nut.

Effect of Hot Water Treatment on Astringency Removal in Persimmon Cultivars

ABSTRACT The aim of this study was to investigate the effect of hot water treatments on the removal of astringency in ‘MKU Harbiye,’ ‘Kaki Tipo,’ and ‘Vainiglia’ persimmon cultivars. Fruits were dipped in tap water at hot water at 40°C for 5 h (HW 40°C-5 h) or hot water at 50°C for 1 h (HW 50°C-1 h). Untreated (Control 1), 20°C for 1 (Control 2, 20°C-1 h), or 5 h (Control 3, 20°C-5 h) and treated fruits were then kept at 20ºC for 10 days of shelf life period. Changes in weight loss, appearance, firmness, total soluble solids, taste, fungal decay, fruit skin color, soluble and insoluble tannin content were determined during shelf life. In all cultivars, HW 40°C-5 h was found to be successful in reducing the astringency and maintained firmness above the marketability limit for 10 days of shelf life period. The fruit treated with HW 40°C-5 h became edible after 7 days at 20°C while control fruits remained astringent based on soluble tannin content the entire shelf-life period. Although the HW 50°C-1 h and Control 2 and 3 (20°C-1 h or 20°C-5 h) treatments received acceptable taste scores after 10 days, fruits from these treatments were slightly astringent.

Effect of hot water treatments on apple fruit rot caused by Fusarium spp.

Hot water treatments of apple fruits prior to long-term storage have a high potential as a physical measure against apple fruit storage rot caused by plant pathogenic fungi. Fusarium species are increasingly found as causal agents of postharvest apple fruit rot. The effect of high temperatures on casual agents of Fusarium fruit rot, F. avenaceum and F. graminearum, was tested in this article. In in vitro assay, spore suspensions of F. avenaceum and F. graminearum were exposed to high temperatures (ranging from 45 to 90 °C) at different duration (ranging from 30 s to 20 min) and the treatments that significantly inhibited mycelial growth of the isolates (53 and 57 °C for 3 and 5 min) were tested in vivo by hot water treatment of inoculated apple fruits of Fuji cultivar. The obtained results showed that the most promising hot water treatment should be between 53 and 57 °C and between 3 and 5 min of the exposure period.

Effect of hot water treatment on dry date preparation from date palm (Phoenix dactylifera) cultivars in arid region

Effect of hot water treatment on dry date preparation from date palm (<i>Phoenix dactylifera</i>) cultivars in arid region

Hot water treatment to alleviate chilling injury and enhance ascorbate-glutathione cycle in sweet pepper fruit during postharvest cold storage

Sweet pepper (Capsicum annuum L.) fruit are highly perishable vegetable and have a short storage life at ambient temperature. The current handling and storage temperatures, below 7 °C, extend the storage life, but chilling injury (CI) occurs after a longer storage. A pre-storage hot water treatment, dipping sweet pepper ‘Miogi’ fruit in 45 °C hot water for 15 min, substantially induced tolerance of fruit to CI at 6 °C storage, and extended storage life for long duration. This research was conducted to reveal the antioxidantive responses of fruit to pre-heat treatment and chilling storage. The purpose of the present study was to understand the effect of hot water treatment on the alleviation of chilling injury and ascorbate-glutathione cycle involved in sweet pepper fruit. Hot water treatment inhibited the increases in malondialdehyde and hydrogen peroxide levels, and enhanced the increases in ascorbate and glutathione contents compared with the control fruit during storage. The activities of ascorbate-glutathione cycle related enzymes including ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase were higher in hot water treated fruit than in the control fruit during cold storage. These results indicate that the alleviation of CI in sweet pepper fruit by hot water treatment in 45 °C hot water for 15 min might be due to the enhancement of the ascorbate-glutathione cycle by increased activity of related enzymes.

Effect of hot water treatment of seeds on quality indicators of alfalfa sprouts

The aim of this study was to evaluate the effect of soaking seeds in hot water on the content of selected bioactive compounds in alfalfa sprouts. Temperature and time regimes were: 85 °C, for 10 and 40 s; 90 °C and 100 °C, for 10 s. Sprouts were examined for the contents of ascorbic acid, chlorophylls a and b, α- and β-carotene, neoxanthin, violaxanthin, lutein and total phenolics. In most cases, the treatment applied had no significant effect on the contents of lutein, violaxanthin, neoxanthin, β-carotene and total phenolics. However, disinfection at 100 °C caused a significant reduction in ascorbic acid content, an increase in total phenolic content and a rise in the proportion of cotyledons in the mass of sprouts. The treatment variants applied did not significantly affect the total chlorophyll content in cotyledons. This study revealed that seed treatment with hot water may, depending on the applied parameters, affect sprout morphology, ascorbic acid content and total phenolic content.

Effect of hot water treatment of in‐shell pecans on physicochemical properties and consumer acceptability of roasted pecan kernels

SummaryThe effect of hot water pre‐treatment of in‐shell pecans on physicochemical properties, consumer acceptance and purchase intent of dehulled and roasted kernels was evaluated. In‐shell pecans were first subjected to hot water at 70, 80 and 90 °C for 8.6, 6.6 and 4.6 min respectively and kernels were later dry roasted at 160 °C for 10 min. The physicochemical properties of hot water treated and untreated nuts, before and after roasting were determined. Furthermore, consumer acceptance and purchase intent of the roasted kernels were determined. Hot water treatment, alone and subsequent roasting had minimal effect on pecans’ physicochemical properties. Consumers liked (P &lt; 0.05) the colour and aroma of treated pecans. No effect (P &gt; 0.05) of pre‐treatment was observed on the acceptability of other sensory attributes. Safety claim increased treated pecans’ overall liking; however, it decreased purchase intent. Hot water treatment showed promise as a post‐harvest microbial intervention strategy without affecting the physicochemical properties and consumer acceptability.

Effect of hot water treatments and storage period on the quality attributes of banana (Musa sp.) fruit

Abstract The current study was carried out to evaluate the effect of hot water treatments and storage period on quality attributes of banana in the laboratory of Farm Structures, Sindh Agriculture University, Tandojam, Pakistan during 2017. Green matured Basari banana fruit free from defects was collected from local fruit market. The samples of banana fruit were dipped for 10 minutes in four different water treatments i.e. control (T1), 40°C (T2), 50°C (T3) and 60°C (T4). The quality attributes of stored banana fruits was observed at initial time of storage and at an interval of five days. The results demonstrated a significant (p≤0.05) effect of hot water treatments and storage period on banana’s quality parameters. Highest values for moisture content (%), pulp firmness (N), pulp to peel ratio, titratable acidity (%) and ash content (%) were observed under T3 followed by T2, T1 and T4, whereas least values for total soluble solids (% brix), pulp pH, total sugar content (%), decay incidence (%) and weight loss (%) were observed for T3 followed by T2, T1 and T4. It was also observed that all quality attributes except moisture content, pulp firmness, titratable acidity and ash content increased with increasing storage period. The conducted study concluded that treatment T3 provided better results, maintaining better quality with minimum losses. Keywords: Basari; Banana; Hot water treatments; Quality attributes; Storage period http://dx.doi.org/10.19045/bspab.2018.700195

Effect of hot water treatment on chilling injury incidence and antioxidative responses of mature green mume (Prunus mume) fruit during low temperature storage

Mume (Prunus mume Sieb. et Zucc.) fruit are harvested and consumed at the mature green stage and have a short storage life at ambient temperature. The current handling and storage temperatures, below 6 °C, extend the storage life to a week, but chilling injury (CI) occurs after a longer storage. A pre-storage hot water treatment, dipping ‘Nankou’ fruit in 45 °C water for 5 min, substantially reduced susceptibility of fruit to CI at 6 °C storage, and extended storage life for three-fold. This research was conducted to reveal the antioxidantive responses of fruit to pre-heat treatment and chilling storage. Hot water treatment inhibited the increases in malondialdehyde and hydrogen peroxide levels, and delayed the decreases in ascorbate contents and total antioxidant capacity levels compared with the control fruit during storage. The activities of antioxidant-related enzymes including ascorbate peroxidase and monodehydroascorbate reductase were higher in hot water treated fruit than in the control fruit during cold storage. These results indicate that the alleviation of CI in mature green fruit by hot water treatment might be due to the protection and enhancement of the antioxidant system by increased activity of related enzymes.

Hot water treatment effect in the elephant grass ashes calcinated at different temperatures

ABSTRACT In recent years, agro-industrial residues have focused attention in the scientific community as a new source of pozzolans. In Brazil, for example, one of the wastes generated from agro-industrial activities comes from elephant grass that is cultivated as biomass for energy cogeneration. This study evaluated the effect of hot water treatment on the crystalline structure of elephant grass ashes calcinated in two different temperature (700 and 900°C). To study the chemical structure and the composition of the ashes the X-ray fluorescence (XRF) and X-ray diffractions (XRD) analyses were carried out. The results achieved in the present work shown that, elephant grass ashes meet the ASTM C-618 standard, for the minimum sum content of the silica (SiO2), aluminum (Al2O3) and iron (Fe2O3) oxides, of 50% to be considered as a pozzolanic material. The presence of an amorphous phase has been detected in all XRD patterns. The ashes calcinated at 700°C showed lower crystallinity and the treatment with hot water decreased crystallite size, i.e., the material became more amorphous. On the other hand, the ashes calcinated at 900°C, less reactive, had a lower content of K2O. Therefore, the hot water treatment was effective to reduce the potassium content in the ashes. Additionally, it contributed to reduce the crystallite size of silica in the ash calcinated at 700°C, while the effect is contrary to the ash calcinated at 900°C.

Impacts of minimal processing and hot water dipping of ‘Sonata’ strawberries on volatiles emitted during storage

Strawberries flavour attributes are important quality parameters that have a significant impact on consumer acceptability. Minimal processing and postharvest treatments in many cases neglect the importance of flavour attributes or sacrifice them for better appearance and/or longer shelf life. In addition, only few information is available on the impact of postharvest handling on flavour attributes. Thus, the objectives of this paper were to investigate: i) the effects of minimal processing on changes in composition and relative abundance (%) of volatile organic compounds (VOCs) emitted from strawberries; and ii) the effects of hot water treatments (45 °C) at different dipping duration (5 and 10 min) on the shift in VOC composition of ‘Sonata’ strawberries. Based on gas chromatography-mass spectrometry (GC–MS) analysis, the volatile profiles obtained for strawberries were significantly (p ≤ 0.05) influenced by minimal processing. Aldehydes were most abundant in strawberry puree (34.1%) compared to sliced samples (17.5%) and none were detected in the headspace of intact fruit. Esters were most abundant in the sliced samples (62.9%) compared to intact strawberries (51.2%) and fruit puree (≈ 49%) samples. Hot water treatment and dipping durations had significant impact on the synthesis of methyl and ethyl esters and acetaldehyde in comparison to the untreated (control) samples (p ≤ 0.05). At the end of storage, concentrations of methyl acetate (4.9 ± 0.86 mg mL−1), methyl butanoate (6.7 ± 0.05 mg mL−1), ethyl butanoate (0.6 ± 0.37 mg mL−1), and acetaldehyde (3.1 ± 0.99 mg mL−1) were lowest in strawberries dipped in hot water at 45 °C for 10 min. In contrast, hot water treatment with dipping duration of 5 min best maintained and enhanced the synthesis of methyl butanoate and prevented the accumulation of methyl isobutyl ketone. This study showed that minimal processing had a significant impact on the volatile profile of ‘Sonata’ strawberries, and that hot water treatments play a crucial role on the emission of volatile compounds.

Effect of hot water treatments on quality of fresh-cut muskmelon fruit (Cucumis meloL.) ‘Honeyworld’

Effect of hot water treatments on quality of fresh-cut muskmelon fruit (<i>Cucumis melo</i>L.) ‘Honeyworld’

Effect of hot water treatment in controlling fusarium wilt of gladiolus

The experiment was conducted at the Horticulture Research Centre (HRC), Bangladesh Agricultural Research Institute (BARI), Gazipur during 2010-12 following two factors RCB design with four replications. The levels of Factor A (Duration): were i) T1 = 5 minutes, ii) T2 = 10 minutes and iii) T3 = 15 minutes. Factor B (Water temperature): i) A1 = 500C, ii) A2 = 520C, iii) A3 = 540C, iv) A4 = 560C and v) A5 = Control (normal water). The treatment combinations were evaluated against the wilt disease of gladiolus (Fusarium oxysporum f. sp. gladioli) under naturally infested field condition. Corm treated with hot water at 540C for 5 minutes was very effective in inhibiting the wilt disease incidence and thereby resulting better corm emergence, flower sticks plot-1, corm plot-1 and comel yield of gladiolus. Corm treated with hot water at 520C for 10 minutes appeared moderately effective against Fusarium wilt as well as better flower, corm and cormel yield of gladiolus under field condition.Bangladesh J. Agril. Res. 42(3): 393-401, September 2017

Defense response against postharvest pathogens in hot water treated apples

Abstract Hot water treatment (HWT) has been demonstrated to be a safe and effective method to control postharvest diseases. In the present study, the effect of HWT (45 °C for 10 min) was investigated on the response of apple fruit against Botrytis cinerea, Colletotrichum acutatum and Neofabraea vagabunda infections. In vivo experiments were conducted with apples treated with HW and then inoculated with pathogen spore suspensions 0, 3, 6 and 24 h after the treatment. In vitro experiments were carried out in order to investigate the HWT effect on the pathogenesis enzyme activities of the three pathogens. These assays were conducted with the crude protein extracts (CPEs) derived from the hot water treated apples. A significant reduction of rot incidence was observed in fruit inoculated at 6 h ( B. cinerea 22.7% and C. acutatum 11.0%) and 3 h ( N. vagabunda 68.8%) after HWT with respect to the controls (22.0, 18.5 and 19.67 mm, respectively). CPEs extracted from hot water treated fruit inoculated at 6 h and 3 h showed the highest conidia germination inhibition ( B. cinerea 85.6%; C. acutatum 52.7% and N. vagabunda 83.1%) with respect to the controls (74.0, 71.0 and 90.3% of conidia germination, respectively). A significant reduction of pathogenesis enzyme activities of the three pathogens was detected when pathogens were exposed to CPEs derived from hot water treated apples. The results showed that HWT can stimulate a defense response on apple against some postharvest pathogens.

Mesocarp RNA-Seq analysis of mango ( Mangifera indica L.) identify quarantine postharvest treatment effects on gene expression

Abstract Quarantine measures to prevent insect dispersion include modified atmospheres or hot water treatment (HWT) for mango. The effects of HWT on mango “Ataulfo” at mature-green and ripe stages on gene expression were evaluated by RNA-seq. 27,629 ORF were annotated according to the non-redundant database and most of the changes in gene expression due to the HWT occurred at the mature-green stage with 903 differentially expressed genes (Log2 fold-change ≥ 4, FDR

Postharvest Diseases and Effect of Hot Water Treatments on White Fleshed Dragon Fruit [Hylocereus undatus (Haw.) Britton &amp; Rose

Postharvest rots are a significant limitation to the storage life of white fleshed dragon fruit, this paper aimed to identify the main pathogens associated with postharvest diseases in the Mekong delta region, to identify the origins of infections, and to investigate the use of heat treatments for postharvest rot control. Dragon fruit were stored at 0°C, 5°C and 10°C for 26 days followed by 3 days shelf life at 20°C. Other fruit were held at 20°C for 7 days as a non-stored control. The main fungi associated with postharvest rots were Alternaria alternata, Bipolaris cactivora, Colletotrichum truncatum, Fusarium dimerum, Fusarium equiseti and Rhizopus stolonifer. Skin pieces plated out from freshly harvested surface sterilised fruit yielded C. truncatum, F. dimerum, F. equiseti, A. alternata, and B. cactivora. Surface swabs from fruit in the field yielded A. alternata and Fusarium sp. The study showed that, except for those caused by R. stolonifer, all postharvest rots of dragon fruit have their origin either as latent infections in the field or as surface-borne spores. Many of the rot pathogens could grow at low temperatures and surface-borne Fusarium and Alternaria species were able to infect the fruit during storage. To test the effect of hot water treatments (HWTs) on postharvest rots, freshly harvested fruit were immersed at 49, 51, 53, and 55°C for two or three minutes, stored at 5-6°C for 28 days and 3 days shelf life. HWTs at 49°C and 51°C for two or three minutes both completely inhibited rots during storage, and after the shelf-life, significantly fewer rots were observed than other HWTs and the untreated control. The 49 and 51°C HWTs also showed the least weight loss no damage to bracts, and no effect on titratable acidity, total soluble solids, fruit firmness, or flesh or skin colour. Current gaps in knowledge of postharvest rots and research strategies to address them are outlined in the paper.

Effect of hot water treatment on development of anthracnose (Colletotrichum gloeosporioides) and quality of mango fruit at Jimma southwest Ethiopia

Anthracnose is the major postharvest disease of mango and occurs throughout mango producing areas of the world including Ethiopia. Evaluating effect of hot water treatment on development of anthracnose and quality of mango fruit is imperative. A total of three hot water levels 48, 52 and 56 °C at two time interval (5 and 10 min) were tested with factorial arrangement in completely randomised design. The study indicated that hot water treatment at different temperatures and time interval significantly (p < 0.001) affects disease development and shelf life and postharvest quality of mango fruits. Hot water treatments reduced the incidence and severity of anthracnose disease significantly (p < 0.001) in mango fruits as compared to control. There was a highly significant difference (p < 0.0001) on weight loss, total soluble solids, titratable acidity and fruit firmness of mango fruits due to treatment. The present study reviled that hot water treatment has a potential in reducing the postharvest loss due to anthracnose and improving the shelf life and quality of mango fruits. However, the reduction of disease pressure on fruits was not at applicable level, which call ups future effort on developing on integrated disease management strategies for reduction of postharvest loss of mango fruits.

Effects of hot water treatments on dormant grapevine propagation materials used for grafted vine production

Agrobacterium vitis is responsible for the crown gall disease of grapevine which breaks the grapevine trunk vascular system. Nutrient flow is prevented by crown gall and it leads to weak growth and death of the plants. It can be destructive disease often encountered in vineyards and it can be spread in cuttings for propagation. Thermotherapy treatment is an alternative method for eradicating A. vitis from grapevine cuttings but effects of thermotherapy treatments on dormant vine tissue, bud vitality, rooting and shooting of the propagation materials are not yet fully understood. In this research, it is aimed to determine the effects of thermotherapy treatment (Hot water treatment) on callus formation (at the basal part and grafting point), grafted vine quality (shoot length, shoot width, root number, shooting and rooting development, fresh and dry weight of shoots and roots) and final take in the grafted vine production. Experiment was conducted in the nursery of Manisa Viticultural Research Institute. Rootstocks (Kober 5BB, Couderc 1613 and 41B) and scions (Sultan 7 and Manisa sultani) were hot-water treated at 50°C for 30 minutes which is the most common technique against Agrobacterium vitis . After thermotherapy treatment, all rootstocks were grafted with Sultan 7 and Manisa sultanivarieties. They were kept for 22 days in callusing room for callus development and then they were planted in polyethlyene bags for rooting. At the end of the study, significant treatment x rootstock interaction were observed for the final take of Sultan 7 variety. Thermotherapy treated of 1613C/Sultan 7 combinations had more final take than the control (untreated) group. For instance, hot water treated cuttings of 1613C/Sultan 7 combinations had 75% final take while the control group had the 70%. Also there were not observed any adverse effects of HWT on bud and tissue vitality.

Physico-chemicals and sensory quality of Peaches treated with hot water during the cold storage

The objectives of this study were to investigate and compare the effects of hot water treatments on the physico-chemical and sensory quality of peach fruit during cold storage. Peach fruit were harvested at physiological mature stage and were treated with hot water at 35oC,40oC , 45oC, 50oC, 55oC, 60oC and control with tap water (20oC) for 2 minutes to evaluate the effects of hot water. Peach fruit were stored at 0°C ±1°C with 90% ± 5% RH for 30 days during the period of analysis. Hot water treatments have significant effect on moisture loss, TSS, pH, acidity, sugar acid ratio, reducing sugar, non-reducing sugar, vitamin C, firmness and organoleptic evaluation of peaches. There was no significant effect of these treatments on the ash content of fruits. Hot water treatment at 50°C for 2 min reduced moisture loss and delay in the increase of TSS, pH, sugar acid ratio, reducing sugar, and decrease in acidity, non-reducing sugar, vitamin C and firmness. Overall, the results indicate that hot water treatment at 50°C has tremendous potential for maintaining physicochemical and sensory quality of peach during cold storage.