Enhancing and Maintaining Nutritional Quality and Bioactive Compounds of “Hayward” Kiwifruit: Comparison of the Effectiveness of Different CaCl₂ Spraying Times

Abstract

This study was conducted to elucidate the effect of calcium chloride (CaCl2) spraying times and number of sprays on the changes in biochemical compounds of “Hayward” kiwifruit (Actinidia deliciosa) during storage as well as at the shelf life. The vines in two different commercial kiwifruit orchards were sprayed with CaCl2 (15 g/L), one, two and three times in 35, 85 and 125 days after full bloom. Fruits were harvested at maturity stage and then were stored at 0C for 90 days and 5 additional days under simulated marketing conditions. The results showed that orchard location had significant effect on fruit biochemical compounds. With a few exceptions, one‐time (early‐, mid‐, late‐season) and twice CaCl2 sprays had no significant effects on kiwifruit quality characteristics. Thrice sprays significantly reduced respiration rate, ethylene production and polygalacturonase activity that lead to delay degradation of vitamin c, phenolic compounds and antioxidant activity, and maintained fruit sensory quality. Overall, thrice sprays of CaCl2 delayed fruit ripening processes and maintained fruit quality of “Hayward” kiwifruit. Practical Applications As the importance of phytochemical content in the health benefits of fruits and vegetables is recognized, interest in the antioxidant activity, enzymes, and polyphenolic and phytochemical contents of kiwifruit has increased significantly in recent years. During cold storage, many physicochemical changes occur that significantly affect fruit quality. Polygalacturonase (PG) is a cell wall‐bound enzyme which has been found to play a role in numerous plant developmental processes such as fruit ripening and softening. Considerable attention has been given to calcium (Ca) application to kiwifruit, since maintenance of relatively high Ca concentrations in fruit tissues results in better nutrients balance, maintaining cell wall stabilization and integrity, retards fruit respiration and ripening by lower rates of CO2 and C2H4 production, PG activity, softening, and finally extends storability. It should also be noted that the beneficial effects of preharvest Ca sprays depend on the time and number of treatments and orchard location.

Effect of Harvesting Stages and Calcium Chloride Application on Postharvest Quality of Tomato Fruits

“…Our findings are in line with those of Addai et al [24], who found that the amount of TPC had a significant effect on different harvesting stages of papaya fruits, and that the amount of TPC increased as maturity stages progressed. However, CaCl 2 increased the polysaccharide content in the fruit cell wall and maintained the strength of the cell membrane, which ultimately prevents the senescence-induced stress and delays the release or oxidize the phenolic compound from the fruit matrix [9]. Although the three-way interaction was non-significant, significant two-way relationships appeared between the harvesting stages × storage times and different levels of CaCl 2 × storage durations on DPPH.…”

“…Numerous physiological and biochemical mechanisms of tomato fruits were believed to be controlled by affiliation of calcium ion (Ca 2+ ) by declining the rate of respiration and ethylene production due to the increasing levels of Ca 2+ in the fruit matrix [8]. Therefore, the postharvest spraying with CaCl 2 showed higher in firmness, lower rate of ethylene and respiration; as a result, fruits showed the delay senescence [9].…”

Biochemical changes in calcium chloride treated Hisar Arun (Local) and Kashi Vishesh (Hybrid) cultivars of Tomato fruit

“…This explains the increment of total phenol content recorded in our investigation. Moreover, calcium prevents senescence-induced stress by main¬taining the strength of its membrane 6 , and thus delays the release of phenolic compounds.…”

“…The rate of ethylene production and respiration in tomato fruits reportedly decreased by increasing the level of calcium ions 5 . Thus, treatment of fruits with CaCl 2 resulted in improving the firmness of the fruits and decreased deteriorations physiologically thereafter leading to reduced respiration, decrement in ethylene production, and delay in fruit ripening 6 . Various investigations revealed that calcium chloride treatment on tomato reduced post-harvest decay quantitatively in terms of development in the lycopene and ascorbic acid content, controlled development of physiological disorders, strengthening of the skin constituting cell walls, and providing the tissues with improved resistance, reduced production of enzymes which thus limit infections, control ripening, and rotting thus inevitably improving the quality and shelf-life of tomato 7 .…”

Effect of chemical pretreatment on quality attributes of the cashew apple

“…They reported that CaCl 2 decreased ethylene production and retained maximum phenolic content after 20 days of storage. Shiri et al (2016) reported that CaCl 2 increases the polysaccharide content in the fruit cell wall and maintains the strength of the cell membrane, which delays the release or oxidation of phenolic compounds from the fruit matrix. This is in-line with results obtained where the lowest reduction in TPC was found in the CaCl 2 treatment.…”