Combination of salicylic acid and ultrasonication for alleviating chilling injury symptoms of longkong

Objectives Chilling injury is a prominent physiological disorder in longkong fruit pericarp when stored under 13 °C for a prolonged period. This study aimed to investigate the effects of individual salicylic acid (SA) and ultrasonication (US) treatments and of the combination salicylic acid and ultrasonication (SA-US) on alleviating the chilling injury symptoms in longkong fruit pericarp when in prolonged cold storage. Materials and methods SA (1 mmol/L) and US (40 kHz, 10 min at 90% amplitude, 350 W) were used as individual and combined (SA-US) treatments to control the chilling injury in longkong pericarp. The various quality measures were checked every 2 days in longkong for up to 18 days of cold storage (13 °C, 90% relative humidity). Results The results revealed that the control fruits treated with water exhibited severe chilling injury symptoms followed in rank order by US, SA, and SA-US cases. Treatments such as US and SA alone were more effective in controlling chilling injuries than control, while only minimal significant differences were noticed between them. On the other hand, the longkong pericarp treated with the SA-US combination had significantly increased antioxidant enzyme (superoxide dismutase and catalase) activities and decreased levels of membrane lytic (phospholipase D and lipoxygenase) enzymes and browning-inducing enzymes (phenylalanine ammonia lyase and polyphenol oxidase). Consequently, in the longkong pericarp, the chilling injury index, electrolytic leakage, respiration rate, weight loss, firmness, malondialdehyde content, changes in unsaturated and saturated fatty acid contents, and reactive oxygen species were significantly controlled by this treatment. Conclusions The present study concludes that longkong fruit treatment with a combination of US and SA is an excellent alternative for controlling the chilling injury symptoms and extending the shelf-life.

Application of Essential Oils for Maintaining Postharvest Quality of ‘Rongrien’ Rambutan Fruit

The postharvest quality of rambutan fruits (Nephelium lappaceum Linn.) is mainly influenced by dehydration, which causes browning of the peel and spinterns. This research investigated the effects of some essential oils—from citronella, clove, kaffir lime, and lemongrass—on ‘Rongrien’ rambutan fruit quality during storage at 13 °C. Screening of effective concentrations from 0.01 to 0.16% was conducted for each essential oil. The results showed that, of the essential oil treatments tested, a kaffir lime oil coating of 0.01% could best maintain the quality of fruits, reducing both weight loss and browning of the peel and spinterns. However, essential oil concentrations exceeding 0.04% severely damaged the fruit pericarp, in which scores of spintern browning were higher than those of peel browning. These results suggest that kaffir lime oil can maintain the postharvest quality of ‘Rongrien’ rambutan fruit as a supplement in some edible coatings.

Formulation and Evaluation of Mangosteen (Garcinia mangostana L.) Fruit Pericarp Extract Gel

The topical antioxidant product may be useful for the treatment of oxidative stress-related skin disorder. This research aimed to evaluate a topical gel formulation of Garcinia mangostana L. fruit pericarp (GMP) extract. GMP extract was formulated into a gel and characterized for its physical properties. The antioxidant activity was evaluated based on the radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. The ability of gel formulation to release GMP extract and promote skin delivery was estimated based on DPPH scavenging method and also compared to that of suspension form. The results showed that the GMP extract gel showed characteristics for topical application. The radical DPPH scavenging activity was confirmed both in GMP extract and GMP extract gel. In vitro study release showed that the GMP extract was released from gel. Some degree of GMP extract was also delivered into the shed snakeskin in vitro. When compared with the suspension form, GMP extract gel provided a more profoundly lower release.

Integrative analysis of metabolome and transcriptome profiles provides insight into the fruit pericarp pigmentation disorder caused by ‘Candidatus Liberibacter asiaticus’ infection

Background Mandarin ‘Shatangju’ is susceptible to Huanglongbing (HLB) and the HLB-infected fruits are small, off-flavor, and stay-green at the maturity period. To understand the relationship between pericarp color and HLB pathogen and the effect mechanism of HLB on fruit pericarp coloration, quantitative analyses of HLB bacterial pathogens and carotenoids and also the integrative analysis of metabolome and transcriptome profiles were performed in the mandarin ‘Shatangju’ variety with four different color fruits, whole green fruits (WGF), top-yellow and base-green fruits (TYBGF), whole light-yellow fruits (WLYF), and whole dark-yellow fruits (WDYF) that were infected with HLB. Results the HLB bacterial population followed the order WGF > TYBGF > WLYF > WDYF. And there were significant differences between each group of samples. Regarding the accumulation of chlorophyll and carotenoid, the chlorophyll-a content in WGF was the highest and in WDYF was the lowest. The content of chlorophyll-b in WGF was significantly higher than that in other three pericarps. There were significant differences in the total content of carotenoid between each group. WGF and TYBGF pericarps were low in phytoene, γ-carotene, β-cryptoxanthin and apocarotenal, while other kinds of carotenoids were significantly higher than those in WDYF. And WLYF was only short of apocarotenal. We comprehensively compared the transcriptome and metabolite profiles of abnormal (WGF, TYBGF and WLYF) and normal (WDYF, control) pericarps. In total, 2,880, 2,782 and 1,053 differentially expressed genes (DEGs), including 121, 117 and 43 transcription factors were identified in the three comparisons, respectively. The qRT-PCR confirmed the expression levels of genes selected from transcriptome. Additionally, a total of 77 flavonoids and other phenylpropanoid-derived metabolites were identified in the three comparisons. Most (76.65 %) showed markedly lower abundances in the three comparisons. The phenylpropanoid biosynthesis pathway was the major enrichment pathway in the integrative analysis of metabolome and transcriptome profiles. Conclusions Synthesizing the above analytical results, this study indicated that different color pericarps were associated with the reduced levels of some carotenoids and phenylpropanoids derivatives products and the down-regulation of proteins in flavonoids, phenylpropanoids derivatives biosynthesis pathway and the photosynthesis-antenna proteins.

Defluoridation of Aqueous Solution Using Thermally Activated Biosorbents Prepared from Adansonia digitata Fruit Pericarp

The presence of fluoride ions in water poses a significant danger to human health. In Tanzania, where the Rift Valley passes, some people are impaired due to elevated levels of fluoride in water. The purpose of this study was to prepare thermally activated Adansonia digitata fruit pericarp biosorbents at 450, 500, 550, and 600°C for defluoridation. Using the Brunauer-Emmett-Teller analyzer, the surface area and pore diameter were measured. The scanning electron microscope and Fourier transform infrared spectrometry were used to determine morphological features and functional groups of biosorbents. To analyze the effect of pH, adsorbent dose, contact time, and initial concentration, the response surface methodology was applied. Adsorption isotherms, kinetics, and regeneration studies were also conducted. There were considerably wide surface areas of 385.44, 399.27, 445.71, and 447.70 m2/g and pore diameters of 0.3055, 3.0341, 3.0375, and 3.0471 nm for biosorbents activated at 450, 500, 550, and 600°C, respectively. FT-IR spectra indicated the oxidation of alcoholic –OH to carboxylic –OH during the activation process, which is proved by the shifting of the peak at 3500-3000 cm-1 from raw biosorbent to a very broad and strong band at 3500-2000 cm-1 from the activated biosorbent. The maximum removal efficiencies of biosorbents activated at 450, 500, 550, and 600°C were 95.55, 96.50, 97.65, and 98.36%, respectively, for all biosorbents at a pH of 2, an initial concentration of 27.50 ppm, a contact period of 75.00 minutes, and an adsorbent dose of 5.50 g, which indicates that the adsorbents were successful for fluoride removal. The isotherms and kinetics indicated that the adsorption fitted well with Freundlich ( R 2 = 0.95661 ‐ 0.98445 ) and pseudo-second-order ( R 2 = 0.94230 ‐ 0.99634 ) kinetic adsorption models, respectively. The results showed that the removal of fluoride by biosorbents prepared is effective and could be used for defluoridation of drinking water.