Reducing postharvest losses and rooting of minimally processed garlic cloves by carboxymethyl cellulose coating as a carrier of peppermint oil and methyl jasmonate

Abstract

The shelf life and economic value of fresh-cut garlic cloves (Allium sativum L.) are severely limited by problems such as browning, rooting, moisture loss, and microbiological spoiling. Edible coatings act as barriers to moisture loss and microbial contamination. In this research, we examined the effectiveness of an edible coating enriched with carboxymethyl cellulose (CMC) and either peppermint oil (PO) or methyl jasmonate (MeJA) on the storability and quality of ready-to-eat garlic cloves. Six treatments were used: CMC (1%), PO (0.5%), MeJA (0.5%), CMC+PO, CMC+MeJA, and a control treatment (distilled water). The garlic cloves were stored for 60 days at 5 °C and 98% relative humidity. After 60 days of storage, CMC, PO, and CMC+PO treatments emerged as the most effective at minimizing weight loss, browning, and respiration rate, and at increasing rooting percentage and length. Among these, CMC enriched with PO or MeJA also best maintained vitamin C content. Notably, all treatments enhanced the fruit's antioxidant profile, yielding elevated total phenolic compounds (TPC) and antioxidant activity relative to the control. On the other hand, all treatments showed lower polyphenol oxidase (PPO) activity relative to the control samples. The microbial counts and mold and yeast were suppressed by all treatments, except CMC, compared to the control. All treatments maintained allicin content compared to the control, with CMC+PO showing superior effects 30 days of storage and MeJA after 60 days of storage. In conclusion, extending the shelf life of garlic cloves could be achieved by employing PO and/or MeJA.