Postharvest Deterioration Research Articles

Preharvest treatment of Agaricus bisporus with methyl jasmonate inhibits postharvest deterioration

Rapid deterioration is a serious problem in postharvest storage of Agaricus bisporus (A. bisporus). Hence, measures to improve shelf-life of the mushroom are of great importance. This study analyzed the effect of preharvest treatment of A. bisporus with methyl jasmonate (MeJA) on the postharvest storage quality. Appearance and texture characteristics were determined during a 10-day storage period at 4 °C, and the results showed that MeJA improved the appearance of A. bisporus by inhibiting browning and color variation. Additionally, weight loss and cellulose content were inhibited in MeJA-treated groups. Consequently, MeJA maintained a dense microstructure and alleviated the decline of fracturability and springiness of the mushroom. Thus, MeJA inhibited deterioration and prolonged postharvest storage period of A. bisporus by enhancing appearance and texture characteristics. These results provide important information on improving postharvest quality in the A. bisporus cultivation industry.

Opportunities to Commercialize Cassava Production for Poverty Alleviation and Improved Food Security in Tanzania

Author(s): Mtunguja, MK; Beckles, DM; Laswai, HS; Ndunguru, JC; Sinha, NJ | Abstract: Cassava is the world's fourth most important staple crop after rice, wheat and maize, and plays an essential role in food security. Due to cassava's growth characteristics and ability to grow in poor soils and regions prone to drought, it is preferred by resourcepoor farmers in many tropical countries. While cassava plays an important role as a food security crop for subsistence farmers, it is prone to rapid postharvest deterioration. Processing cassava for starch is another strategy for overcoming post-harvest losses, can add value to end products and has the potential to create additional employment opportunities along the supply chain. Cassava starch is an important source of biomaterial for different food and non-food industrial applications. Moreover, farmers producing cassava can increase their income by finding alternative end uses to home consumption. To meet the high demand for cassava in Tanzania, cultivar selection, production and processing all need to be improved. Enabling policies that create satisfactory business opportunities for small holder farmers, traders and processors for starch industries is also critical. The aim of this review is to explore the potential of the cassava subsector to contribute to the economy of sub-Saharan countries, particularly Tanzania, and to present how industrial use of domestic cassava starch can help tackle problems of unemployment and food security.

Integration of sugarcane production technologies for enhanced cane and sugar productivity targeting to increase farmers' income: strategies and prospects.

The idea of doubling the farmers' income in next 5years has been slated by the Government of India. The specific target of increasing sugarcane farmers' income could be achieved by developing cost-effective technologies, transferring them from laboratory to land, educating the farmers and creating a linkage between all stakeholders. Consistent efforts shall be required to harness all possible sources for increasing farmer's income in and outside the agriculture sector with respect to improvement in sugarcane and sugar productivity, enhancement in resource use efficiency and adopting various other ways and means including intercropping, management of pests and diseases, use of biotechnological tools and minimizing post-harvest deterioration. The advances in sugarcane biotechnology could become remarkable in the coming years, both in terms of improving productivity as well as increasing the value and utility of this crop substantially. In future, genetically modified sugarcane varieties with increased resistance to different biotic and abiotic stresses would serve more towards sugarcane crop improvement. Any possibility of enhancement in the income of sugarcane farmers shall also be dependent upon the profitability and sustainability of the sugar industry. Integration of sugarcane production technologies for improvement in farm productivity, diversified sugarcane production system, reduced cost of cultivation along with increased processing plant efficiency and diversification to produce value added products shall ensure smooth and higher payment to the farmers. Development of low-cost technologies to convert "waste to resource" on a smaller scale shall also help the farmers to increase their income further. This paper focuses on possible measures to be taken up in each aspects of sugarcane cultivation including biotechnological approaches to achieve the goal of enhancing the income of sugarcane farmers substantially, particularly in the sub-tropical region of India.

Determination of Major Factors Associated with Fungal Contamination of Wheat Under Storage Conditions

Storage fungi are among the major factors causing post-harvest deterioration of crop produce worldwide. However, their association to the major factors that contribute to fungal contamination under storage conditions remains under studied in many parts of Sub-Saharan Africa including Ethiopia. Therefore, the current work was carried out with the objectives to identify major factors that contribute to fungal contamination of wheat grains under storage conditions. For this purpose mycological analysis was carried out using 180 wheat grain samples collected from three major wheat growing zones (Arsi, West Arsi and Bale) of South East Ethiopia. Results of the mycological analysis revealed the contamination of wheat grains by fungal species at different locations and storage time with different frequencies. Fungal contamination of samples indicated that highest incidence was observed at West Arsi (96.98%) followed by Bale (91.76%) and Arsi (86.43%). Fungal contamination also varied with storage period with the highest incidence of (98.62%) followed by (89.78%) and (86.77%) was observed after six months, upon harvest and three months of storage, respectively. The highest fungal incidence (98.62%) was recorded after six months storage of wheat grain. Fungal incidence was highly associated with two of the independent variables, namely, temperature and relative humidity of storage in a logistic regression model. However, there is no significant association (p<0.05) with grain moisture content and storage type of wheat grains under storage conditions.

Preharvest β-aminobutyric acid treatment alleviates postharvest deterioration of ‘Bluecrop’ highbush blueberry fruit during refrigerated storage

We examined the effect of preharvest β-aminobutyric acid (BABA) treatment on postharvest quality and the softening of ‘Bluecrop’ highbush blueberry fruit during postharvest refrigerated storage. Reddish purple-colored fruit on shrubs were treated with 20 mM BABA and harvested 7 days after treatment when they turned dark purple. The harvested fruit were stored in clear polyethylene terephthalate clamshells at 2 °C for up to 20 days. Preharvest BABA treatment significantly delayed color changes, enhanced individual soluble sugars and organic acids, and reduced decay incidence. BABA-treated fruit also retained higher skin firmness throughout the storage period. Cell wall materials, closely associated with fruit softening, were significantly higher in BABA-treated fruit than in control. Moreover, preharvest BABA treatment significantly enhanced fruit pectin content at harvest and reduced activities of polygalacturonase and endo-1,4-β-xylanase, although hemicellulose content was unchanged. These results suggest that preharvest BABA treatment alleviates the deterioration of postharvest quality in ‘Bluecrop’ highbush blueberry fruit including skin firmness during refrigerated storage.

Postharvest Losses and their Determinants: A Challenge to Creating a Sustainable Cooking Banana Value Chain in Uganda

Postharvest losses (PHL) result in direct food and income losses to farmers and consumers globally. PHL reduction strategies offer unique opportunities to contribute to sustainable food systems for increased food security and farm incomes for more than 200 million food insecure people in sub-Saharan Africa. Lack of empirical information remains a major challenge to operationalization of PHL reduction strategies in many countries of the region. This paper utilizes cross-sectional data to determine the extent and factors that are influencing postharvest losses in the cooking-banana value chain in Uganda. We find that 14.9% of all the cooking bananas that are produced in Uganda suffer postharvest deterioration along the value chain (7.2% of the bananas deteriorate completely and have no residual value, while 7.7% deteriorate partially and are sold at discounted prices), mostly affecting retailers. At farm level, female headed households experience more losses than those headed by males. Household headship, household size, proportion of land allocated to banana production, and monthly banana production are the principal determinants of PHL at farm level. At retail level, such losses are mainly determined by sex of the vendor and group membership. The findings call for comprehensive and gender-responsive PHL reduction strategies.

Melatonin is involved in the regulation of postharvest physiological deterioration and quality of cassava tuberous roots

Melatonin is involved in the regulation of postharvest physiological deterioration and quality of cassava tuberous roots

EFFECT OF SOME POSTHARVEST TREATMENTS ON FRUIT QUALITY AND STORABILITY OF WINTER GUAVA (PSIDIUM GUAJAVA L.) ETMANY STRAIN

Guavas are climacteric, perishable fruits and have very short life after harvest. Postharvest treatments of fruits by using oxalate or gibberellic acid and storage at low temperature can enhance storability of guava fruits without quality deterioration. This experiment was conducted in seasons (2015 and 2016) to evaluate the effect of potassium oxalate, ammonium oxalate and gibberellic acid (GA3) either alone or in combinations as postharvest treatments on physical and chemical changes of winter Guavas strain ‘Etmany’ during storage at 8±1°C plus two days at 18-23°C as shelf life. Nine treatments were applied as follows: control (distilled water), 30 mM of potassium oxalate, 30 mM of ammonium oxalate, 50 or 100 ppm of GA3 and 30 mM of potassium oxalate or ammonium oxalate in combination with 50 or 100 ppm of GA3. The treated fruits were dipped in aqueous solution for 10 minutes. All treatments significantly reduced the deterioration in physical and chemical attributes compared to control treatment during cold storage and shelf life. Also, these treatments significantly minimized physiological loss in weight, reduced decay incidence, maximized marketable percentage, maintained visual appearance score, increased firmness, hue angle and lightness. Moreover, fruits treated with 30 mM of potassium or ammonium oxalate in combination with 100 ppm of GA3 possessed the best values in comparison with either control or the other treatments. Thus, it is been recommended from the results, to use the combination of potassium or ammonium oxalate and GA3 as a promising method for delaying postharvest deterioration and keeping fruit quality during cold storage up to 21 days at 8°C and 2 days shelf life at 18-23°C.

Compositional shifts in the surface fungal communities of apple fruits during cold storage

The demands for fruit postharvest quality and safety improvement rely on a better understanding of the overall fungal communities during cold storage. Here, we characterized the superficial fungi of 18 apple samples before and after cold storage by sequencing internal transcribed spacer 1 (ITS1) sequences. High quality sequences (1,319,679) clustered into 512 operational taxonomic units (OTUs), representing 261 fungal species belonging to four phyla, 22 classes, 59 orders, 93 families, and 134 genera. The cold stored (CS) samples were harboured with 81,752 high-quality ITS reads and 265 OUTs per sample, which were higher than those of harvest point (HP) samples (averaged 64,879 ITS reads and 217 OTUs). Additionally, the CS samples obtained higher fungal richness, evenness and diversity than those of HP samples. Beta diversity analysis revealed significant fungi compositional differences between CS and HP samples. At the genus level, Acremonium, Monascus, Archaeorhizomyces, Yarrowia were highly detected in original HP samples, but reduced their abundance during cold storage; Penicillium, Aspergillus, Mucor, Botrytis, Mycosphaerella, Rhodotorula and Wallemia were significantly proliferated in CS samples. The increases level of Penicillium, Aspergillus, Mucor, and Botrytis during the apple storage, potentially suggest that the long-term stored apples contain more risks of fruit postharvest deterioration and patulin contamination. This study identified fungal communities on apples and their variations in cold storage, and provides a basis for further fruit fungi investigation.

Identification and Functional Characterization of Sugarcane Invertase Inhibitor (ShINH1): A Potential Candidate for Reducing Pre- and Post-harvest Loss of Sucrose in Sugarcane.

In sugarcane, invertase enzymes play a key role in sucrose accumulation and are also involved in futile reactions where sucrose is continuously degraded during the pre- and post-harvest period, thereby reducing sugar yield and recovery. Invertase inhibitor (INVINH) proteins play a key role in post-translation regulation of plant invertases through which sucrose hydrolysis is controlled. INVINH proteins are small (18 kDa) members of the pectin methylesterase inhibitor superfamily and they are moderately conserved across plants. In the present study, we identified two INVINH genes from sugarcane, ShINH1 and ShINH2. In silico characterization of the encoded proteins revealed 43% sequence identity at the amino acid level, confirming the non-allelic nature of the proteins. The presence of putative signal peptide and subcellular targeting sequences revealed that ShINH1 and ShINH2 likely have apoplasmic and vacuolar localization, respectively. Experimental visualization of ShINH1–GFP revealed that ShINHI is indeed exported to the apoplast. Differential tissue-specific and developmental expression of ShINH1 between leaf, stalk, flower and root suggest that it plays a role in controlling source-sink metabolic regulation during sucrose accumulation in sugarcane. ShINH1 is expressed at relatively high levels in leaves and stalk compared to flowers and roots, and expression decreases significantly toward internodal maturity during stalk development. ShINH1 is expressed at variable levels in flowers with no specific association to floral maturity. Production of recombinant ShINH1 enabled experimental validation of protein function under in vitro conditions. Recombinant ShINH1 potently inhibited acid invertase (IC50 22.5 nM), making it a candidate for controlling pre- and post-harvest deterioration of sucrose in sugarcane. Our results indicate that ShINH1 and ShINH2 are likely to play a regulatory role in sucrose accumulation and contribute to the improvement of sugar yield and recovery in sugarcane.

Characterization of enzyme-liquefied soursop (Annona muricata L.) puree

Soursop (Annona muricata L.) is a tropical fruit that undergoes rapid postharvest deterioration. Conversion into puree is a way to value add the fruit. Pectinex® Ultra SP-L, Celluclast® 1.5 L, and Fungamyl® 800 L (0–5% v/w) were used to treat fruit pulp and pectinase at 1.5% (v/w) concentration was chosen as the primary enzyme in combined enzymes study because it produced the best result in liquefaction. A liquefied puree with reduced viscosity of up to 50% (15.20 ± 0.17 mPas) was obtained when pectinase was used in combination with cellulase compared to puree treated with pectinase only. Physicochemical results showed the addition of cellulase did not lead to significant changes (P > 0.05) in pH, titratable acidity, and ascorbic acid but caused significant increases (P ≤ 0.05) in total soluble solid and total sugar content. Aroma profile analyzed using a zNose™ showed at least 15 volatile compounds were detected in fresh soursop fruit with methyl hexanoate (MH) (0.023 ± 0.004%) and methyl trans-2-hexenoate (MTH) (0.014 ± 0.002%) as the major volatile compounds. Principal Component Analysis (PCA) indicated six important variables were selected as the principle component which generated total cumulative variance of 92.9%.

Molecular markers reliably predict post-harvest deterioration of fresh-cut lettuce in modified atmosphere packaging

Fresh-cut lettuce is popular, but highly perishable product. Genetic studies of two bi-parental populations derived from crossing parents with rapid and slow rates of deterioration showed that the deterioration rate is a heritable trait (broad spectrum heritability, H2 of 0.56–0.87). The major genetic determinant of the deterioration rate in both populations was the quantitative trait locus (QTL), qSL4, located on linkage group 4. This QTL explained 40–74% of the total phenotypic variation of the trait in the two populations. Saturating the qSL4 region with single-nucleotide (SNP) markers allowed detection of six haplotypes in a set of 16 lettuce accessions with different rates of deterioration. Three of the haplotypes were always associated with very rapid rates of deterioration, while the other three haplotypes were associated with slow rates of deterioration. Two SNPs located 53 bp apart were sufficient to separate the 16 accessions into two groups with different rates of deterioration. The accuracy of markers-trait association was subsequently tested on 350 plants from seven F2 families that originated from crossing parents with different rates of deterioration. The H2 of deterioration rate in these seven families ranged from 0.64 to 0.90. The SNP-based analysis accurately identified individuals with rapid, intermediate, and slow rates of deterioration in each family. Intermediate rate of deterioration was found in individuals having heterozygous alleles at qSL4, indicating an additive effect of the alleles. The assay can be used for fast, accurate, and reliable identification of deterioration rate after processing for salad.

Effect of 60 Co gamma irradiation on postharvest quality and selected enzyme activities of Volvariella volvacea

Abstract Volvariella volvacea fruit bodies were exposed to six different dosage levels (0, 0.2, 0.4, 0.6, 0.8, and 1.0 kGy) of 60Co gamma ray source, and then stored at 16 °C and 55–60% relative humidity for 7 d. Storage of the 0.8-kGy treatment group resulted in the highest sensory evaluation score, (increase by 51.85% than other treatments). The activity of selected enzymes involved in postharvest deterioration were also studied. The results showed that irradiation treatments have achieved significantly better commercial appearance after 7 d of storage due to slower postharvest mushroom softening, browning, weight loss (10.53%–34.73%) and respiration rate (17.20%-48.72%) than control. respectively.Samples irradiated with the 0.8-kGy dose performed better than other treatments. The control showed a significantly higher malonaldehyde (MDA) level than the irradiated samples (5.5%–45.27%). Increased catalase (CAT) activity (P

Using volatile organic compounds to monitor shelf-life in rocket salad

Rocket salad (Diplotaxis tenuifolia or Eruca sativa) is a perishable product of increasing interest due to its high content of nutritionally relevant compounds including glucosinolates and vitamin C. There is an increasing consumption of ready-to-eat salads which are sold to the consumer in bags, often packed under modified atmosphere. Shelf-life and sell-by dates are commonly applied to these products and are usually dictated by the appearance of the product rather than its nutritional value. During shelf-life, postharvest deterioration leads to a loss of nutritionally relevant compounds such as vitamin C. This is accelerated by suboptimal conditions during storage and transport such as breaches of the cold-chain. Volatile organic compounds (VOCs) are easy and quick to sample use of thermal desorption gas chromatography time of flight mass spectroscopy (TD-GC-TOF-MS) enables remote sampling and a very sensitive analysis of VOC profiles. We have used TD-GC-TOF-MS to sample VOCs from rocket salad bags sourced from a local supermarket to assess changes during the shelf-life of the product. Using statistical analyses that treat the whole VOC profile as a single variable we show that it is possible to differentiate between day of purchase, use by date and time points beyond sale. We conclude that this methodology is therefore of use for assessing rocket salad quality through the supply chain.

Genetic inheritance of pulp colour and selected traits of cassava (Manihot esculenta Crantz) at early generation selection.

The early generation selection of cassava quantitative and qualitative traits saves breeding resources as it can shorten breeding schemes. Inheritance analysis provides important breeding information for developing new improved varieties. This study aimed at developing an F1 segregating cassava population and determining mode of gene action of pulp colour and selected traits at early generation selection (F1 seedling and clones). The 15 families exhibited significant (P < 0.05) phenotypic variation between offspring. The general combining ability (GCA) was significant for all traits except cassava brown streak disease on leaves, whereas specific combining ability (SCA) was significant for all evaluated traits. The Garukansubire and Gitamisi genotypes were the best general combiners for improving fresh storage root yield, while G1 and G2 were the best general combiners for improved carotenoid (yellow/orange pulp colour) and delayed physiological postharvest deterioration. The pulp colour had the highest GCA/SCA ratio and percent sum of squares due to GCA. The 15 F1 families exhibited essential genetic diversity for cassava improvement. The expression of most cassava traits was controlled by both additive and non-additive gene action. The study elucidated the role of dominance effects over the additive effects for the evaluated traits. However, the pulp colour was predominantly controlled by additive gene action. This implies the possibility of improving cassava through conventional breeding using recurrent selection for most traits. © 2017 Society of Chemical Industry.

Food security: a plant pathology perspective.

Abstract Food Security has four dimensions: food availability, food access, economic access to food and food utilization. There is a fifth dimension, sometimes referred to as stability of food. Embedded within each of these four dimensions are sub-dimensions. Historically, production was the focus of concern, but today there is more interest in imports and stockpiles because almost every country in the world today relies on trade and imports with food security. No country is totally self-sufficient in food in today's environment. Plant diseases play a major role in the production of food. Their influence on food security is expressed by the epidemics they cause, the reduction in production and post-harvest deterioration reducing available food for a hungry world.

Identification of Postharvest Senescence Regulators Through Map-Based Cloning Using Detached Arabidopsis Inflorescences as a Model Tissue.

Postharvest deterioration of fruits and vegetables can be accelerated by biological, environmental, and physiological stresses. Fully understanding tissue response to harvest will provide new opportunities for limiting postharvest losses during handling and storage. The model plant Arabidopsis thaliana (Arabidopsis) has many attributes that make it excellent for studying the underlying control of postharvest responses. It is also one of the best resourced plants with numerous web-based bioinformatic programs and large numbers of mutant collections. Here we introduce a novel assay system called AIDA (the Arabidopsis Inflorescence Degreening Assay) that we developed for understanding postharvest response of immature tissues. We also demonstrate how the high-throughput screening capability of AIDA can be used with mapping technologies (high-resolution melting [HRM] and needle in the k-stack [NIKS]) to identify regulators of postharvest senescence in ethyl methanesulfonate (EMS) mutagenized plant populations. Whether it is best to use HRM or NIKS or both technologies will depend on your laboratory facilities and computing capabilities.

Effect of Surface Coatings on the Shelf life and Quality of Cassava

Cassava (Manihot esculenta) is grown as an important dietary source of carbohydrates for communities in a number of African countries. However, Cassava is susceptible to postharvest physiological deterioration which affects its quality and leads to the unpalatability and unmarketability of roots after harvest. Edible surface coatings have been found to be effective in preserving the quality of various perishable food products. This study was undertaken with the objective of determining the best combinations and concentrations of both xanthan gum and guar gum capable as a technology for extending the shelf life of harvested cassava roots. Cassava (variety KME 1) was harvested at physiological maturity. The coating formulations used were: 1%, 1.5%, 2% guar gum, 1.5%, 2%, 2.5% xanthan gum, and 1%, 1.5%, and 2.5% xanthan guar/gum combination in the ratio of 1:1 with some roots left as control. Sampling was done at 2-day intervals for 20 days. The coated cassava showed lower respiration and ethylene production rates than the control samples while change in quality parameters; phenols, colour, flesh firmness, weight loss and dry matter content was significantly (P≤0.05) delayed in the coated samples. The results suggested that using 1.5% xanthan guar/gum as an edible coating, cassava shelf life can be extended by upto 20 days at 25 °C.

Proteomics analysis to understand the ABA stimulation of wound suberization in kiwifruit

Quick suberin-based healing after wounding played a protective role for plant to prevent further damage. In this study, the stimulative effect of exogenous abscisic acid (ABA) on wound suberization in postharvest kiwifruit was evaluated through suberin staining with toluidine blue O as well as the determination of suberin phenolics and aliphatics in wound tissue. Furthermore, to reveal the regulatory involvement of ABA in wound suberization, comparative quantitative proteomics and transcriptomics analyses based on iTRAQ and qRT-PCR technique were performed. In proteomics levels, a total of 95 protein species consistently showed differential abundance between ABA and control, including 29 down-regulated and 66 up-regulated protein species. The Kyoto Encyclopedia of Genes and Genomes (KEGG) with protein-protein interaction analyses revealed that ABA mainly affected the antioxidant system, phenylpropanoid metabolism and lipid metabolism associated with wound suberization. Based on the data of proteomics analysis, the differential expressions of genes encoding 11 selected protein species were confirmed by qRT-PCR analyses. GSH-Px, MDHAR, SOD, APX, POD, PAL, CCR, PPO, CYP86B1, DGGT and KCS11 were likely to be the key enzymes that involved the response of ABA to stimulate wound suberization by mediating the antioxidant system, phenylpropanoid metabolism and lipid metabolism. Biological significanceKiwifruit is susceptible to physical injury causing postharvest deterioration during harvest, transportation and storage. Therefore, quick healing is important for maintaining the postharvest quality of injured fruit. This work elucidated the potential role of ABA and the proteomic mechanism of its regulation in wound suberization of postharvest kiwifruit.

Analysis of phenotypic variability for yield and quality traits within a collection of cassava (Manihot esculenta) genotypes

Genetic diversity is essential for crop improvement and knowledge of the genetic variability within a breeding population facilitates its future exploitation. This study examined the phenotypic and genetic variability for specific cassava key traits in a collection of 30 genotypes at five environments in Rwanda. Seventy-three percent of the variation in dry matter content (DMC) and 98% of the variation in total carotene (TC) content was explained by genotypes. The broad-sense heritability (Hbs) of TC was high (99.2%) and the predicted genetic advance (GA; %) from selection was 159.7%. The phenotypic variance coefficients for all traits were higher than the genotypic variance coefficients. The highest Hbs (%) and GA for carotenoids was an indication that conventional breeding could improve carotenoid content in cassava using simple recurrent selection. The postharvest physiological deterioration (PPD) showed significant (p < 0.05) negative correlation and interrelation with TC and DMC, indicating that the high-TC and low-DMC cultivars could have delayed PPD. The higher-TC genotypes could be used to improve TC in the cassava population and consequently could contribute to the development of delayed-PPD cultivars. The results confirm that there is useful variation for key traits within the collection that could be indicative of a broad range of useful variability in natural populations, landraces and cultivars that could be exploited for breeding.