Improvement of postharvest quality, secondary metabolites, antioxidant activity and quality attributes of Prunus persica L. subjected to solar drying and slice thickness.

Peach is a fruit highly appreciated by consumers; however, it is highly perishable, so drying is an alternative to preserve its physical and chemical properties. In this study, the effect of different drying methods (oven, solar, and open sun) and slice thicknesses (0.5, 1.0, and 1.5 cm) on quality, shelf life, color, total phenol, flavonoid, reducing sugar, non reducing sugar, ascorbic acid contents and antioxidant capacity of peach (Prunus persica L. Cv. Indian blood red), were evaluated. The results showed that, 0.5 cm slice thickness recorded the best results with minimum moisture content (%), drying time (7 hrs), titratable acidity (%), reducing sugars (%), non-reducing sugars (%), total soluble solids (°Brix), disease incidence (%), drying rate, TSS-Acid ratio, ascorbic acid, color and flavor, and total phenolic contents. Storage conditions showed significant results on 90 days of storage with maximum total soluble solids (°Brix), TSS-Acid ratio, reducing sugars (%), minimum titratable acidity (%), ascorbic acid, disease incidence (%), and non-reducing sugars (%), while color and flavor also retained. Peach fruits sliced at 0.5 cm thickness and dried in a solar collector may be considered best to retain the bio chemical attributes for 90 days and solar collector considered as environmentally friendly technology.

Physiological response, phytochemicals, antioxidant, and enzymatic activity of date palm (Phoenix dactylifera L.) cultivated under different storage time, harvesting Stages, and temperatures.

The quality of date palm is highly influenced by postharvest techniques, storage, and processing effects. Fruits stored at room temperature result in dehydration, whereas higher temperatures accelerate the enzymatic browning of fruit. This study aimed to enhance postharvest quality of date palms through improved harvesting and storage techniques. The fruits of date palm (Phoenix dactylifera L. cv. Dhakki) were harvested at khalal (mature, firm), rutab (fully ripe), or tamar (dry) stages and stored at different temperatures (12, 18, or 24 °C) for 0, 15, 30, or 45 days. The analysis of the data showed that the studied attributes significantly different at various ripening stages and storage temperatures. The fruits harvested at Khalal stage proved to be the best in retaining moisture content (23.16%), total soluble solids (20.36 oBrix), fruit juice pH (4.97), ascorbic acid (24.65 mg 100 g-1), non-reducing sugars (26.84%), percent acidity (0.39%), antioxidant activity (211.0 mg 100 g-1), total phenolic (40.07 mg100g-1), flavonoids (45.8 mg 100 g-1), tannin (70.7 mg100g-1), catalase (1.82 U g-1), peroxidase (1.4 U g-1), soluble protein (38.2 mg kg-1), brightness (29.9), chroma (16.4), hue angle (34.9), color (16.8), and with minimum weight loss (8.48%) as compared to fruit harvested at Rutab and Tamar stage. Regarding the means for storage temperature, the fruits stored at 12 ± 3 °C retained the highest moisture content (23.2%), total soluble solids (13.5 oBrix), fruit juice pH (5.42), percent acidity (0.29%), ascorbic acid (24.4 mg100g-1), reducing sugars (31.1%), non-reducing sugars (26.5%), antioxidant activity (214.6 mg100g-1), total phenolic (41.6 mg100 g-1), flavonoids (44.7 mg100 g-1), tannin (71.7 mg 100 g-1), catalase (1.56 U g-1), peroxidase (1.21 U g-1), soluble protein (31.8 mg kg-1), brightness (28.8), chroma (15.3), hue angle (29.6), color (16.2),with minimum weight loss (9.91%). It was concluded that for quality fruit production of date palm cv. Dhakki could be harvested at Khalal stage and stored at a temperature of 12 ± 3 °C.

Application of RNAi technology: a novel approach to navigate abiotic stresses.

BACKGROUND: Due to the rising population globally, and the demand for food, it is critical to significantly increase crop production by 2050. However, climate change estimates show that droughts and heatwaves will become more prevalent in many parts of the world, posing a severe danger to food output. METHODS: Selective breeding based on genetic diversity is falling short of meeting the expanding need for food and feed. However, the advent of modern plant genetic engineering, genome editing, and synthetic biology provides precise techniques for producing crops capable of sustaining yield under stress situations. RESULTS: As a result, crop varieties with built-in genetic tolerance to environmental challenges are desperately needed. In the recent years, small RNA (sRNA) data has progressed to become one of the most effective approaches for the improvement of crops. So many sRNAs (18-30nt) have been found with the use of hi-tech bioinformatics and sequencing techniques which are involved in the regulation of sequence specific gene noncoding RNAs (short ncRNAs) i.e., microRNA (miRNA) and small interfering RNA (siRNA). Such research outcomes may advance our understanding of the genetic basis of adaptability of plants to various environmental challenges and the genetic variation of plant's tolerance to a number of abiotic stresses. CONCLUSION: The review article highlights current trends and advances in sRNAs' critical role in responses of plants to drought, heat, cold, and salinity, and also the potential technology that identifies the abiotic stress-regulated sRNAs, and techniques for analyzing and validating the target genes.

Thin layer drying kinetics and quality dynamics of persimmon (Diospyros kaki) treated with preservatives and solar dried under different temperatures.

Poor postharvest handling, microbial infestation, and high respiration rate are some the factors are responsible for poor storage life of perishable commodities. Therefore, effective preservation of these commodities is needed to lower the damages and extend shelf life. Preservation is regarded as the action taken to maintain desired properties of a perishable commodity as long as possible. Persimmon (Diospyros kaki) is perishable fruit with high nutritive value; however, has very short shelf-life. Therefore, effective preservation and drying is needed to extend its storage life. Drying temperature and preservatives significantly influence the quality of perishable vegetables and fruits during drying. The current study investigated the effect of different temperatures and preservatives on drying kinetics and organoleptic quality attributes of persimmon. Persimmon fruits were treated with preservatives (25% honey, 25% aloe vera, 2% sodium benzoate, 1% potassium metabisulfite, and 2% citric acid solutions) under different drying temperatures (40, 45, and 50°C). All observed parameters were significantly affected by individual effects of temperatures and preservatives, except ash contents. Similarly, interactive effects were significant for all parameters except total soluble sugars, ash contents, and vitamin C. Generally, fruits treated with citric acid and dried under 50°C had 8.2% moisture loss hour-1, 14.9 drying hours, 0.030 g H2O g-1 hr-1, 1.23° Brix of total soluble solids, 6.71 pH, 1.35% acidity, and 6.3 mg vitamin C. These values were better than the rest of the preservatives and drying temperatures used in the study. Therefore, treating fruits with citric acid and drying at 50°C was found a promising technique to extend storage life of persimmon fruits. It is recommended that persimmon fruits dried at 50°C and preserved in citric acid can be used for longer storage period.

Callus Induction, Proliferation, Enhanced Secondary Metabolites Production and Antioxidants Activity of Salvia moorcroftiana L. as Influenced by Combinations of Auxin, Cytokinin and Melatonin

Abstract: Tissue culture technique is one of the best methods to reproduce salvia plant Therefore, the aim of this research was to enhance the in-vitro callus proliferation and production of secondary metabolites of S. moorcroftiana using different combinations of auxin, cytokinin and melatonin. Initially, callus induction was optimized using indole acetic acid (IAA), 2, 4-dichlorophenoxy acetic acid (2,4-D), and naphthalene acetic acid (NAA) applied at different concentrations in combination with 1 mg L-1 of 6-benzylaminopurine (BAP). The results indicates that earliest days to callus induction (14.67 days) was occurred in the media fortified with 2, 4-D+BAP (2.0+1.0 mgL-1). Whereas the highest callus initiation (100%) was induced on MS medium incorporated with 2,4-D+BAP (1+1mgL-1). Furthermore, maximum fresh weight was obtained when 2,4- D + BAP at the rate of (1+ 1mg L-1) was incorporated and dry weight was attained when 2,4- D + BAP at the rate of (2+1 mg L-1) was added to MS media. The maximum fresh and dry weight was obtained when melatonin at rate of 1.5 mg L-1 was supplemented with MS media including 2,4-D + BAP (1+1mg L-1), moreover the maximum DPPH scavenging activity, total phenolic and flavonoid content was noted when supplemented with melatonin at rate of 1.5 mg L-1. In conclusion, among various concentrations of plant growth regulators, 2,4- D + BAP at the rate of (1+ 1mg L-1) along with 1.5 g L-1 melatonin was the best for callus growth and production of secondary metabolites of S. moorcroftiana.

Microbe-assisted phytoremediation of environmental pollutants and energy recycling in sustainable agriculture.

The perception of phytoremediation is efficiently utilized as an eco-friendly practice of green plants combating and cleaning up the stressed environment without harming it. The industrial revolution was followed by the green revolution which fulfilled the food demands of the growing population caused an increase in yield per unit area in crop production, but it also increased the use of synthetic fertilizers in agriculture. Globally, the intensive use of inorganic fertilizers in agriculture has led to serious health problems and irreversible environmental damage. Biofertilizers improve the growth of the plant and can be applied as an alternative to chemical/synthetic fertilizers. Cyanobacteria, bacteria, and fungi are known as some of the principal microbe groups used to produce biofertilizers that form symbiotic associations with plants. Microorganisms perform a key role in phosphate solubilization and mobilization, nitrogen fixation, nutrient management, biotic elicitors and probiotics, and pollution management (biodegradation agents), specifically bacteria which also help in atmospheric nitrogen fixation and are thus available for the growth of the plant. Management or biodegradation of hazardous chemical residues and heavy metals produced by a huge number of large-scale industries should be given primary importance to be transformed by various bacterial strains, fungi, algae. Currently, modern omics technologies such as metagenomic, transcriptomic, and proteomic are being used to develop strategies for studying the ecology of microorganisms, as well as their use in environmental monitoring and bioremediation. This review briefly discusses some of the major groups of microorganisms that can perform different functions responsible for plant health, crop production, phytoremediation and also focus on the omics techniques reportedly used in environmental monitoring to tackle the pollution load.