Bio-preservation Potential of Leaf Extracts of Ocimum gratissimum L. on Fresh-Cut Fruits of Citrullus lanatus (Thunb)

Abstract

This study was conducted to assess the retail market edibility quality of Citrullus lanatus fresh-cut fruits enhanced with the extracts from the leaves of Ocimum gratissimum. Analytical graded ethanol and hexane were used to extract O. gratissimum leaves differently. The fresh-cut fruits were dipped in the extract obtained from the leaves and reconstituted with Tween 80, fruits treated with Tween 80 and untreated fruits were used as controls. The treated fruits with the extracts, fruits treated with Tween 80 and fruits without treatment were analysed for quality test using the following parametres: carotenoids, ascorbic acids, total phenolic acid, pH, total soluble solids, microbial loads and moisture contents at day 0 and at an interval of 3, 5 and 9 days. The quantitative estimations of the phytochemicals in the extracts were determined and the constituents in the essential oil of the hexane extracts were established with the use of GC-MS system, and the data generated from the study were analysed with SPSS 20.0. This study showed that there was lower reduction in moisture content, pH, ascorbic acid and potential browning values of the treated fresh-cut fruits of C. lanatus, compared to higher reduction in untreated and tween 80 treated fresh-cut fruits during the storage intervals for nine days. The treated fresh-cut fruits had higher Brix values of TSS, total phenolic acid and carotenoids contents, compared with the untreated fresh-cut fruit, which was low during the period of storage for nine days. The microbial loads in the untreated fresh-cut fruit of C. lanatus were higher than what was obtained in the treated fresh-cut fruits of C. lanatus after nine days of storage. The yield of Alkaloids from ethanol and hexane extracts were 54.25±0.09 mg/100g and 51.86±0.06mg/100g respectively. γ-Terpinene (17.21 %) and (E)-9-Octadecenoic acid (11.848 %) had the highest percentage composition of phytoconstituents present in the essential oil from Citrullus lanatus. This study was able to establish the preservation potential of Ocimum gratissiumum on fresh-cut fruits of Citrullus lanatus.

Keywords: Citrullus lanatus; Food Safety; Ocimum gratissiumum; Quality parametres