Postharvest quality and bioactive properties of tomatoes (Solanum lycopersicum) stored in a low-cost and energy-free evaporative cooling system

Development and evaluation of earth air heat exchanger cum evaporative cool system as an energy-efficient method for storage of tomatoes

BACKGROUND

The lack of adequate on-farm storage facilities is one of the leading causes of enormous postharvest losses of fresh commodities, negatively affecting farmers' livelihoods and the sector's economic contribution. The aim of the current study was to develop and evaluate a solar-powered earth air heat exchanger cum evaporative cooling (EAHE-EC) system as an energy-efficient method for the storage of fresh produce for smallholders.

RESULTS

The postharvest quality parameters of tomatoes stored under ambient storage (AS) and in an EAHE-EC system were assessed at regular time intervals during storage. These include weight loss, total soluble solids, titratable acidity, fruit firmness, color, pH, ascorbic acid, lycopene content, total phenolic acid, and antioxidant activity. The average temperature and relative humidity inside the EAHE-EC system varied from 20.59 to 22.61 °C and 82.60% to 89.43%, respectively, in comparison with AS (26.39-39.21 °C and 22.09-43.58%). Storage methods and time had a significant (P < 0.05) effect on tomato quality. Based on the retention of the overall quality until the end of the storage period, the shelf life of tomatoes was recorded as 21 days in the EAHE-EC system, which was 1.5 times more than AS (14 days).

CONCLUSIONS

The extra shelf-life gained by tomatoes in the EAHE-EC system may provide a sufficient buffer period for smallholders for retailing and marketing. This suggests that the developed system can maintain postharvest quality and increase the shelf life of tomatoes. It therefore has potential as an energy-efficient system for the storage of fruits and vegetables, including tomatoes. © 2023 Society of Chemical Industry.

Postharvest Quality Improvement of Bell Pepper (Capsicum annuum L. cv Nagano) with Forced-Air Precooling and Modified Atmosphere Packaging

Optimum postharvest storage conditions increase the postharvest quality and shelf life of horticultural crops. The effects of forced-air precooling (FAP) and modified atmosphere packaging (MAP) on shelf life, physicochemical quality, and health-promoting properties of bell pepper (Capsicum annuum L. cv. Nagano) harvested at 90 and 50% coloring stages in May and July respectively, stored at 11 °C, 95% relative humidity were assessed. Fruits were subjected to four treatments: FAP + 30 μm polyethylene liner (FOLO); FAP-only (FOLX); 30 μm polyethylene liner-only (FXLO); and control (FXLX). The quality attributes, viz. weight loss, firmness, color, soluble solids content (SSC), soluble sugars, total phenolic content (TPC), total flavonoid content (TFC), 2,2-dephenyl-1-picrylhydrazyl (DPPH), and 2,2'-azino-bis-3-ethylbenzo-thiazoline-6-sulfonic acid (ABTS) were evaluated. The investigated parameters differed significantly (p < 0.05) among treatments except for soluble sugars. FOLO maintained sensory quality (weight loss, firmness, and color), physicochemical (SSC and soluble sugars), and health-promoting properties compared to other treatments during storage. The 50% coloring fruits had a huge variation between treatments than 90% coloring. The results revealed more TPC and antioxidant capacity in the 50% than in the 90% coloring fruits. The study highlights the need to consider the ideal fruit coloring stage at harvest under the effect of FAP and MAP treatments in preserving bell pepper's postharvest quality and shelf life.