Starch‐based antifungal edible coatings to control sour rot caused by Geotrichum citri‐aurantii and maintain postharvest quality of ‘Fino’ lemon

Abstract

BACKGROUND: Two edible coating (EC) emulsions based on potato starch (F6 and F10) alone or formulated with sodium benzoate (SB, 2% w/w) (F6/SB and F10/SB) were evaluated to maintain postharvest quality of cold-stored 'Fino' lemons and control sour rot on lemons artificially inoculated with Geotrichum citri-aurantii. Previous research showed the potential of these ECs to improve the storability of 'Orri' mandarins and reduce citrus green and blue molds caused by Penicillum digitatum and Penicillium italicum, respectively. RESULTS: The coatings F6/SB and F10/SB significantly reduced sour rot incidence and severity compared to uncoated control samples on lemons incubated at 28 °C for 4 and 7 days. The F6/SB coating reduced weight loss and gas exchange compared to uncoated fruit after 2 and 4 weeks of storage at 12 °C plus a shelf life of 1 week at 20 °C, without adversely affecting the lemon physicochemical quality. CONCLUSION: Overall, the F6/SB coating formulation, composed of pregelatinized potato starch, glyceryl monostearate, glycerol, emulsifiers and SB, with a total solid content of 5.5%, showed the best results in reducing citrus sour rot and maintaining the postharvest quality of cold-stored 'Fino' lemons. Therefore, it showed potential as a new cost-effective postharvest treatment suitable to be included in integrated disease management programs for citrus international markets with zero tolerance to chemical residues.

Chitosan and other edible coatings to extend shelf life, manage postharvest decay, and reduce loss and waste of fresh fruits and vegetables

“…the cherry tomato [43]. Starch-based coatings control pathogenic fungi and bacteria only if amended with antifungal ingredients, such as essential oil and sodium benzoate [44][45][46]. Therefore, the combination of different edible coatings with compounds presenting antifungal properties has emerged as alternative technology to protect fresh product from postharvest pathogenic fungi.…”

Starch‐Based Coatings for Food Preservation: A Review

“…In these studies was speculated that the SC containing SB could be a suitable alternative to substitute conventional chemical fungicides used to inhibit molds in fruits. [37,50] Although PSo and SB are GRAS additives, further studies must be addressed to investigate the migration of these antimicrobials into foods, as well as their effect on the rheological properties of starch solutions.…”

Synthesis, Characterization, and Investigation of Coating Properties of Carboxymethyl Acorn Starch (CMAS)

“…[16][17][18][19] In addition, CMS is also used in fruit and vegetable coatings, as it is a relatively renewable and biodegradable starch derivative. [20][21][22][23] Fruits and vegetables lose weight through transpiration during postharvest processing, handling, transportation, and storage, causing textural changes and surface shrinkage that affects their shelf life. Edible coatings have emerged as an effective and environmentally friendly alternative to extend their shelf life and protect them from harmful environmental influences.…”