Quality Of Litchi Fruit Research Articles

Influence of girdling on growth, flowering and fruiting in Litchi cv. Late Bedana

The present investigation was carried out at farmer’s field, Sainik Farm, Patharchatta, Pantnagar, District Udham Singh Nagar, Uttarakhand. The experiment was conducted to study the effect of girdling on growth, flowering and fruiting attributes in Litchi cv. Late Bedana. Twenty-year-old litchi trees consisted of seven treatments with two level of girdling severity of 25% and 50% primary branches in combination of girdling width of 2 mm, 4 mm and 6 mm, along with ungirdled control which were tested with randomized block design with three replications. The results indicated that all the litchi trees which were subjected to different severity and width of girdling had more flowering intensity (%) fruit set (%) and fruit retention (%) and girdling also reduced fruit drop as compared to control. However, the treatment girdling of 50% of primary branches + 4 mm wide had significant effect on improving fruit set (38.44%) and fruit retention (14.07%). Girdling blocks the downward flow of carbohydrate from leaves to roots thus the carbohydrate may accumulate above the girdled portion which resulted in additional supply of carbohydrates from leaves to fruits, therefore, the fruit yield and fruit quality of litchi may increase.

Postharvest hydrogen sulfide infiltration modulates antioxidative metabolism and increases shelf life of litchi

Litchi fruits are highly perishable in nature and start deteriorating immediately after harvest, which can be characterized by pericarp browning. In this study, the effect of exogenous hydrogen sulfide (H2S) on different biochemical events linked to pericarp browning and oxidative damage in litchi were assessed at 1 day interval during 4 days storage. Fruits were vacuum infiltrated with H2S (1 and 2 mM) at ambient temperature. The untreated control fruits were subjected to dipping in distilled water and were stored at ambient (28 °C, RH 70–75%) conditions. H2S treatment maintained the postharvest quality of litchi fruit during storage by alleviating oxidative damage and modulating enzymatic activities. Control fruits lost their postharvest quality at initial storage with visible pericarp browning and other biochemical degradative changes when compared with treated fruits. Postharvest H2S (2 mM) infiltration significantly reduced weight loss, pericarp browning and ROS production (H2O2 and O2−) as well as suppressed the activity of polyphenol oxidase (PPO) and peroxidase (POD) enzymes and exhibited higher TSS, titratable acidity, total phenolic, anthocyanin, antioxidant activities, membrane integrity, phenylalanine ammonia lyase (PAL) activity and reduced quinone and malondialdehyde (MDA) accumulation. Thus, H2S (2 mM) infiltration treatment could be suggested to enhance the storage life of litchi fruits at ambient storage condition.

Effect of postharvest treatments on shelf life and quality of litchi stored at ambient temperature

Treatments that extend the postharvest life are essential in developing countries like Bangladesh, where the infrastructure of the cold chain is often lacking. The shelf life and quality of litchi fruits treated with, calcium chloride, oxalic acid 2 mM + bavistin 0.05% + ice, ice treatment, ice + oxalic acid 2 mM + bavistin 0.05%, ice + oxalic acid 2 mM, wash with clean water and control (no treatment); and two postharvest packaging system, i.e., non-packaging and low-density polyethylene (LDPE) packaging were studied. All tested treatments indicated a significant delay in the change of disease incidence, shelf life, physiological loss in weight, firmness, pericarp browning index, total soluble solids (TSS), titratable acidity, vitamin C content, and pH in postharvest litchi fruits compared to control. The decreased rate was lower in physiological weight loss and disease incidence in fruits coated with oxalic acid 2 mM + bavistin 0.05% + ice in combination with the use of polyethylene bags at ambient temperature.

Effect of carboxymethyl cellulose and chitosan as edible coating layer on quality of litchi fruits during preservation

Effect of carboxymethyl cellulose and chitosan as edible coating layer on quality of litchi fruits during preservation

Drying kinetics, antioxidants, and physicochemical properties of litchi fruits by ultrasound-assisted hot air-drying.

To obtain better qualities of litchi fruits, fruit pulps were subjected to ultrasonic treatment (UT) followed by drying. Samples were subjected to UT at 3W/g for 10min with distilled or ice water and compared with non-UT dried samples. After drying, vitamin C, total phenolic content, color, texture, nutrition, microbial load, drying kinetics, and shelf life were assessed. Results suggest that shear stress plus increasing heat reduced drying time by about 50%, and retained 70% vitamin C and 60% total phenolic content. UT led to about 75% of vitamin C and 70% total phenolic content through inhibition of ultrasonic heat. No significant differences were found in redness, yellowness, and hardness. Inhibition of ultrasound heat resulted in about 27% glucose, 22% fructose, 17% sucrose, and prolonged storage time. Inhibition of increasing ultrasound heat allows low drying cost and high product quality of litchi fruit in air-drying. PRACTICAL APPLICATIONS: UT promotes drying efficiency and preserves product quality. However, this treatment triggers the loss of antioxidants and sugars of litchi fruits when water temperature arises in the treatment. Additional use of ice crystals can offset the thermal effect of the UT; this mechanism reduces the diffusion and loss of nutrients from the material to the solution. This strategy is simple and feasible to improve the drying rate and to retain the content of antioxidants, and further improve the flavor and storage quality of dried litchi fruits.

Apple polyphenols delay senescence and maintain edible quality in litchi fruit during storage

The present study evaluated the impacts of exogenous apple polyphenols (AP) treatment on senescence-related physiological characteristics and edible qualities in ‘Dingxiang’ litchi fruit during storage at ambient temperature (25°C). The results exhibited that 5 g L−1 AP treatment effectively delayed the development of litchi pericarp browning, and browning indices from 4 to 8 in AP-treated fruit averaged 40% lower than those in control fruit. AP treatment reduced the respiration rate and weight loss in litchi fruit during storage. AP application to litchi fruit slowed the changes in glucose and fructose contents while inhibiting the decline in sucrose. AP treatment also resulted in higher contents of organic acids (malic acid, citric acid, succinic acid, and tartaric acid), phenolic compounds (caffeic acid, chlorogenic acid, (+)-catechin, (-)-epicatechin, rutin and total phenolics), ascorbic acid and glutathione, consequently contributing to maintenance of flavor and nutritional quality in litchi fruit., Moreover, compared to control fruit, AP treatment improved antioxidant capacity in litchi fruit, as indicated by higher DPPH radical-scavenging activity and ferric ion reducing antioxidant power (FRAP). The findings suggest that AP application could be a promising postharvest strategy to delay senescence and maintain edible quality of litchi fruit.

Chitosan biopolymer improves the fruit quality of litchi (Litchi chinensis Sonn.)

Chitosan (CHT) is a natural compound that has been used to control postharvest pathogenic diseases due to its capability of eliciting natural defense responses in plants. The aim of this study was to investigate the effect of foliar CHT application on yield and quality of the litchi fruit. Chitosan was applied by spraying on to fruit and foliage just after fruit set four times at 7-day intervals with four varying doses viz. 100, 250, 500, and 1,000 µg L<sup>−1</sup> and a control (0 µg L<sup>−1</sup>). Although the application of CHT had no significant effect on the size of the fruits (length and width), the total contents of phenolics, flavonoids, and ascorbic acid and the antioxidant activity of litchi fruit arils were significantly increased in CHT-treated fruit compared with the untreated control. The highest phenolic, flavonoid, and ascorbic acid contents were 334 µg gallic acid g<sup>−1</sup>, 881 μg quercetin g<sup>−1</sup>, and 178 µg g<sup>−1</sup>, respectively, in fruits treated with 500 µg L<sup>−1</sup> CHT. However, the highest antioxidant activity (622 μg butylated hydroxytoluene g<sup>−1</sup>) was recorded in 250 µg L<sup>−1</sup> CHT-treated fruits. Our findings revealed that the application of low doses of CHT in a litchi orchard might improve fruit quality by increasing the content of antioxidants and antioxidant activities.

Identification of volatile organic compounds for the biocontrol of postharvest litchi fruit pathogen Peronophythora litchii

Litchi is an important economic fruit in subtropical countries. The litchi downy blight (LDB) caused by the oomycete Peronophythora litchii severely affects the production and quality of litchi fruit, and is widespread in almost all litchi production regions of China. Therefore, there is an urgent need for effective and sustainable control strategies against LDB. Our previous study showed that Bacillus amyloliquefaciens LI24 and PP19, B. licheniformis HS10, B. pumilus PI26, and Exiguobacterium acetylicum SI17 are promising biocontrol agents (BCAs) in controlling LDB, and their volatile organic compounds (VOCs) could inhibit the growth of P. litchii in vitro. In this study, we found that pre-exposure of litchi fruit to VOCs produced by PP19, SI17 and PI26 can significantly reduce the severity of LDB during 36 h to 72 h post inoculation. We further analyzed VOCs produced from the three BCAs (i.e., PP19, SI17, PI26) by solid phase microextraction gas chromatography-mass spectrometry (SPME-GC–MS), and found that their chemical compositions varied substantially over incubation time and between BCAs. In total, 70, 98, 101 chemicals were detected in PP19, SI17, PI26 from 24 to 72 h of incubation, respectively; 17 of them were commonly produced at more than one time points by PP19, and 11 were selected for further study. Two of the compounds 1-(2-Aminophenyl)ethanone (EA) and Benzothiazole (BTH) showed inhibitory activity against both P. litchii on plates and LDB on litchi fruit when the compounds were directly applied, while another compound α-Farnesene (AF) was able to suppress LDB in vivo, but did not exhibit antagonistic activity against the pathogen in vitro, suggesting that it may act through induction of host defense mechanisms. Our results showed that the bacterial VOCs and compounds of BTH or AF could be promising for the control of LDB on harvested litchi fruit.

Effect of micronutrients and plant growth regulators on yield and fruit quality of litchi (Litchi chinensis Sonn.) cv. Muzaffarpur under foot hills of Arunachal Pradesh

The present investigation to study the effect of micronutrients and plant growth regulators on growth, yield and fruit quality of litchi (Litchi chinensis Sonn.) cv. Muzaffarpur under the foothills of Arunachal Pradesh was carried out during 2016 at Fruit Research Farm, Department of Fruit Science, College of Horticulture and Forestry, Central Agricultural University, Pasighat, Arunachal Pradesh. The experiment was laid out in Randomized Block Design with 9 treatments and 3 replications. The treatments were T1=ZnSO4 foliar spray @ 0.4 percent, T2=ZnSO4 foliar spray @ 0.8 percent, T3=Borax foliar spray @ 0.4 percent, T4=Borax foliar spray @ 0.8 percent, T5=2,4 -D foliar spray @ 10 ppm, T6=2,4 -D foliar spray @ 20 ppm, T7=GA3 foliar spray @ 20 ppm, T8=GA3 foliar spray @ 40 ppm and T9=Control.

Hydrocooling delays pericarp browning, enzymatic activities and maintains quality of litchi fruits under cold chain conditions

The role of hydrocooling on storage life of litchi (Litchi chinensis Sonn.) cultivar ‘Dehradun’ was investigated. The bunches of litchi fruits cv. Dehradun were harvested at the physiological mature stage i.e. when fruit attained full rosy red colour. Thereafter, small bunches of about half kilogrammes fruits were prepared and subjected to hydrocooling treatments for 10, 20 and 30 min. The temperature of water was maintained at 4°C with auto-cut refrigeration system. The fruits without hydrocooling were kept as control treatment. The temperature of cooling media and fruit pulp was regularly monitored with digital thermometer. Immediately after giving hydrocooling treatments, fruits were air-dried to remove the surface moisture and thereafter packed in corrugated fibre board boxes and stored in walk-in-cold room maintained at temperature 2–3°C and 90–95% relative humidity. The stored samples were evaluated periodically at weekly interval till four weeks various physiological, biochemical parameters and enzymatic activity. The results of the study indicated that litchi fruits hydrocooled for 30 min. maintained lower physiological weight loss (3.88%), browning index 3 (¼ to ½ browning), retained higher organoleptic score (7.15 out of 9), TSS (19.14°B), acidity (0.32%), total anthocyanins (0.31 δA/g FW) and total phenols (246.33 mg/100 g) during storage. The fruits subjected to hydrocooling for 30 min. also maintained the lowest activity of PPO activity as compared to control and other treatments. The study demonstrates the effectiveness of hydrocooling treatment in prolonging the storage life of litchi fruits for 21 days as compared to 7 days in case of control fruits.

Effects of dry fog humidification on pericarp browning and quality of litchi fruit stored at low temperature

Pericarp browning is the major cause of deterioration of harvested litchi fruit. Water loss plays a role in pericarp browning of litchi fruit. This study investigated the effects of humidification with dry fog on pericarp browning and quality of litchi fruit stored at low temperature. Litchi fruit were stored in a non-humidified cold chamber (control) or in a humidified cold room using Tabor atomizer system that generated 95% relative humidity (RH) without depositing water on the fruit surface at 4°C. Control fruit stored in cold room without added humidity underwent rapid weight loss, accompanied by severe pericarp browning after 25 d of storage. However, slight weight loss and no obvious pericarp browning were found in humidified-fruit. Moreover, humidification maintained well the integrity of cell membrane and inhibited polyphenol oxidase activity during early storage. In addition, respiration rate was obviously inhibited in humidified-fruit compared with control fruit. This study might provide a convenient approach to reduce pericarp browning of harvested litchi fruit by humidifying the fruit using the Tabor atomizer at low temperature instead of packaging with film. Keywords: litchi, pericarp browning, dry fog, high relative humidity, cold storage DOI: 10.25165/j.ijabe.20191204.4420 Citation: Xiao L, Li T T, Jiang G X, John A, Zhang D D, Jin W Y, et al. Effects of dry fog humidification on pericarp browning and quality of litchi fruit stored at low temperature. Int J Agric & Biol Eng, 2019; 12(4): 192–196.

Yield and fruit quality of litchi (Litchi chinensisSonn.) under the influence of organic and inorganic nutrient management practices

Yield and fruit quality of litchi (<i>Litchi chinensis</i>Sonn.) under the influence of organic and inorganic nutrient management practices

Effects of gellan-based coating application on litchi fruit quality traits

Effects of gellan-based coating application on litchi fruit quality traits

Quality Detection of Litchi Stored in Different Environments Using an Electronic Nose.

The purpose of this paper was to explore the utility of an electronic nose to detect the quality of litchi fruit stored in different environments. In this study, a PEN3 electronic nose was adopted to test the storage time and hardness of litchi that were stored in three different types of environment (room temperature, refrigerator and controlled-atmosphere). After acquiring data about the hardness of the sample and from the electronic nose, linear discriminant analysis (LDA), canonical correlation analysis (CCA), BP neural network (BPNN) and BP neural network-partial least squares regression (BPNN-PLSR), were employed for data processing. The experimental results showed that the hardness of litchi fruits stored in all three environments decreased during storage. The litchi stored at room temperature had the fastest rate of decrease in hardness, followed by those stored in a refrigerator environment and under a controlled-atmosphere. LDA has a poor ability to classify the storage time of the three environments in which litchi was stored. BPNN can effectively recognize the storage time of litchi stored in a refrigerator and a controlled-atmosphere environment. However, the BPNN classification of the effect of room temperature storage on litchi was poor. CCA results show a significant correlation between electronic nose data and hardness data under the room temperature, and the correlation is more obvious for those under the refrigerator environment and controlled-atmosphere environment. The BPNN-PLSR can effectively predict the hardness of litchi under refrigerator storage conditions and a controlled-atmosphere environment. However, the BPNN-PLSR prediction of the effect of room temperature storage on litchi and global environment storage on litchi were poor. Thus, this experiment proved that an electronic nose can detect the quality of litchi under refrigeratored storage and a controlled-atmosphere environment. These results provide a useful reference for future studies on nondestructive and intelligent monitoring of fruit quality.

Effect of controlled atmosphere storage on pericarp browning, bioactive compounds and antioxidant enzymes of litchi fruits

‘Gola’ litchi fruits were stored under ten different CA-combinations at 5±1°C to investigate its effects on pericarp browning, biochemical quality and antioxidative activities. Control fruit turned completely brown after 28days of storage and were excluded from the study. Fruit-stored under CA7-combination (1% O2+5% CO2) showed reduced weight loss, pericarp browning, membrane leakage and malondialdehyde contents. Soluble solid contents, titratable acidity and ascorbic acid contents were higher in CA7-stored fruit. Activities of catalase and superoxide dismutase enzymes, levels of total anthocyanins, DPPH radical-scavenging-activity and phenolic contents were significantly higher in CA7-stored litchi fruit. In contrast, activities of polyphenol oxidase and peroxidase enzymes were substantially lower in fruit kept under CA7-combination. Fruit subjected to CA7-conditions also maintained higher organoleptic quality. In conclusion, 1% O2+5% CO2 CA-conditions delayed pericarp browning, maintained antioxidative activities and biochemical characteristics along with better organoleptic quality of litchi fruit for 35days.

Hierarchical response surface methodology for optimization of postharvest treatments to maintain quality of litchi cv. ‘Thieu’ during cold storage

Pericarp browning and microbial decay considerably reduce the shelf life and economic value of litchi fruit. In this study a hierarchical response surface methodology with a multiple response criterion was applied to litchi cv. ‘Thieu’ cultivated in Vietnam to determine the optimal postharvest treatment factors throughout the whole storage period. Instrumental measurements were used to analyze quality attributes of fruit at harvest and after 10d, 20d, 30d, and 38d. Sensory quality was evaluated after 30d and 38d of storage. The optimal postharvest treatment for export fruit in which no fungicide residue is allowed consisted of dipping fruit for 10min in a 5.84mM oxalic acid solution and draining them. For fruit intended for local and regional consumption, the optimal treatment consisted of dipping it for 1min in a 0.053% solution of carbendazim then for 10min in a 5.14mM oxalic acid solution, and finally draining. In both cases, fruit were packed in a polypropylene bag with a relative perforation area of 0.011% and stored at 4±1°C. The overall quality of litchi fruit was thus maintained throughout 38d of storage.

Quality assessment of litchi fruits grown in different growing systems in new alluvial zones of West Bengal

A study was conducted during the year 2010–2012 to assess the fruit quality of litchi (Litchi chinensis Sonn.) grown in organically and conventional system in new alluvial zones of West Bengal. Findings revealed that organically grown fruits contained more amount of Ca, Fe, Mn and P as compared to conventional (use of chemical fertilizer) grown fruits. Organically grown fruit also exhibited maximum quality parameters like total soluble solids, total sugar, TSS: acid and fruit weight while maximum yield (kg/tree) was obtained from conventional grown trees.

Reducing postharvest pericarp browning and preserving health promoting compounds of litchi fruit by combination treatment of salicylic acid and chitosan

Litchi (Litchi chinensis Sonn.) is one of the important fruit crops of the subtropical region. The fruit is highly perishable in nature and losses its commercial value within 1–2 days after harvest due to pericarp browning and deterioration in fruit quality. In the present study, effect of postharvest treatment with salicylic acid (0.5mM and 1.0mM) and chitosan (2%) on reducing pericarp browning and preserving functional and sensory quality of litchi fruit was investigated. Physiologically mature litchi fruits (cv. Purbi) were treated with salicylic acid (0.5mM and 1.0mM) and chitosan (2%) alone or in combination by dipping method for 5min. Following treatments, fruits were air-dried and stored at 4°C for 6 days. The results showed that among the applied treatments, salicylic acid (1.0mM) in combination with chitosan (2%) was highly effective in reducing pericarp browning, weight loss, decay loss and maintaining higher anthocyanins, phenolics, flavonoids, ascorbic acid and antioxidant capacity than control fruits. This treatment showed 1.4-fold lower pericarp browning, 1.6-fold lower weight loss and 6.7-fold lower decay loss than control. It also maintained 88% higher anthocyanin, 47% higher total phenolics, 29% higher total flavonoids and 35% higher total antioxidant capacity than control fruits. It also delayed increase in total soluble solids content in litchi fruit during storage. There was no significant effect of treatments on titratable acidity during storage but ascorbic acid content was maintained higher in treated fruits. Thus, combination treatment of 1.0mM salicylic acid and 2% chitosan can be used to reduce pericarp browning and preserving quality of litchi fruit during postharvest storage.

Development of a model for quality evaluation of litchi fruit

Sensory quality of litchi fruit is closely related to the appearance, flavor and nutritional quality. Principle component analysis (PCA) and multi-linear regression analysis (MLR) were performed to select the crucial quality factors in determining litchi sensory quality, and then a mathematical model was established to evaluate the litchi quality. Sensory evaluation value was conducted by a trained panel while sixteen instrumental quality parameters were used, including color (L*, a* and b*), single fruit weight (SFW), total soluble solids (TSS), pH, crude protein (CP), vitamin C (Vc), titratable acid (TA), glucose, fructose, sucrose, malic acid (MA), tartaric, edible rate (ER), and juice yield (JY). The PCA result demonstrated that six principle components exhibited high relationship with sweet and sour degrees, color, ER, TSS, Vc, CA and JY, which accounted for 82.359% of the original variables, and MLR results indicated that the crucial quality parameters were SFW, TA, a*, and ER. The predicted model was established in which validity QLOO2=0.603>0.5 in leave-one-out cross validation. Cluster analysis was used to select the cultivars suitable for eating quality which can provided a guide for litchi production and breeding.

Preharvest application of abscisic acid promotes anthocyanins accumulation in pericarp of litchi fruit without adversely affecting postharvest quality

Pericarp colour of litchi fruit is an important quality attribute that determines its market value and consumer acceptance. Plant growth regulators (PGR) such as abscisic acid (ABA) and ethephon are known to play important roles in peel colour development during maturation and ripening of non-climacteric fruits (e.g. grape and litchi). Our aim was to investigate the effects of preharvest application of ABA, ethephon and their combination on pericarp colour and fruit quality of litchi (cv. Calcuttia) and also to assess the potential effects on postharvest performance of fruit. Exogenous application of ABA (150 or 300mgL−1) at the colour-break stage significantly increased the concentration of total anthocyanins and cyanidin-3-O-rutinoside, the major anthocyanin contributing ∼71–96% of the total anthocyanins, in litchi pericarp compared to ethephon (500μLL−1). Among different anthocyanins quantified, the relative contribution of cyanidin-3,5-diglucoside to the total anthocyanins was significantly higher in all PGR-treated fruit compared to the control, but the concentration of cyanidin-3-O-glucoside was specifically enhanced by ABA. No significant effect on the concentrations of epicatechin, and quercetin-3-O-rutinoside was observed in response to PGR treatments. Ethephon (500μLL−1) treatment did not significantly increase the anthocyanin levels in pericarp, but it caused more degradation of chlorophyll pigments than control. Aril quality with regard to firmness, soluble solids and acidity was not significantly affected by PGR treatments, except that ethephon-treated fruit showed significant softening and lower acidity. Postharvest changes in fruit quality attributes including pericarp browning during cold storage at 5°C for 14 d were mainly related to the storage duration effect, rather than PGR treatment. In conclusion, ABA treatment (150 or 300mgL−1) at the colour-break stage enhanced anthocyanins accumulation in litchi pericarp without adversely affecting postharvest quality and storage stability for 14 d.