Calcium-related Post-harvest Physiological Disorders of Fruits and Vegetables in Eswatini: A Review

Abstract

Calcium (Ca2+) related physiological disorders of fruits and vegetables are abnormalities of fruits and vegetables which are not caused by infectious diseases, insects, nematodes or animals. Fruit and vegetable abnormalities occur due to environmental stress, nutritional deficiencies or excess on the plant. In this study, information was sought through informal surveys, review of literature and interviews with key post-harvest handling and storage participants and direct observation of fruits and vegetables in the markets. Calcium related post-harvest physiological disorders of fruits and vegetables encountered in this study included: cavity-spot, black end and cork, bronzing, skin freckles, fruit and crown, fasciation, soft-nose/spongy-tissue, granulation, low temperature breakdown/flesh browning, water-core, senescent-breakdown, superficial-scald, bitter pit, leaf tip-burn, golden specks and blossom-end rot. Post-harvest physiological disorders result in direct economic losses and pose a threat to food and nutritional security. Various ways of alleviating particular Ca2+ related post-harvest related physiological disorders are suggested e.g. addition of Ca2+ containing fertilisers and Ca2+ sprays.

Calcium Ascorbate Coating Improves Postharvest Quality and Storability of Fresh-Cut Slices of Coscia and Abate Fétel Pears (Pyrus communis L.)

“…The delayed softening observed here could be attributable to the higher calcium level in fruit tissue, in addition to the advantage of calcium ascorbate in preventing browning. Calcium (Ca 2+ ) is an important mineral for fruit as it helps to maintain cell wall integrity and fruit quality [36]. While suppressing polygalacturonase (PG) activity, the production of calcium pectates and membrane system stability improved the stiffness of the middle lamella and cell walls [11].…”

“…At this stage and until seven days of storage, the ASC treated fre cut slices kept the highest firmness values. However, 12 days after storage, the firmn of both the ASC treatment and the untreated fruit dropped to the lowest values (Figu and fruit quality [36]. While suppressing polygalacturonase (PG) activity, the prod of calcium pectates and membrane system stability improved the stiffness of the lamella and cell walls [11].…”

The Effects of Edible Coatings on the Postharvest Quality of Citrus Fruits as Affected by Granulation

“…is means that the enzyme activities are higher in granulated fruits as compared with those in the healthy fruits. Wenqin [21] Adverse atmospheric condition: cold weather during the maturity period [5,20] Sink competition among the different plant parts, i.e., fruits, roots, and leaves.…”

“…[9, 22, 23] Rootstocks and cultivars type [3,24] Higher water potential in juice cells [25] High temperatures during flowering and fruit set [12] Calcium deficiency [20] Enzymes activity: polyphenol oxidase (PPO), peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), pectinmethylesterase (PME), and cellulose [26] et al [26] have also reported that the inbred pumelo fruits have higher granulation than hybridized fruits. Researchers also noted that no new isoenzymes appear when both inbred and hybridized pumelo fruits are granulated.…”

“…Among those plant nutrients, calcium was reported to be highly effective in the prevention of granulation in citrus. On the other hand, the selection of cold tolerant and early maturing varieties is suggested [20].…”