Nutritional composition of fresh and spoilt tomato (Solanumlycopersicum L.) fruits and associated spoilage fungi in Delta state, Nigeria

Abstract

Tomatoes, rich in minerals, amino acids, sugar and dietary fibre contribute to balanced diet consumed fresh or cooked in sauces and soup dishes. Recently, due to improper postharvest handling, tomatoes have become increasingly contaminated with spoilage microorganisms while consumers prefer damaged fruits due to rising costs. This study aimed to identify the spoilage fungi and compare the proximate composition of fresh and spoilt tomatoes obtained from five markets in Delta State, Nigeria, with the objective of informing consumer choices and health implications. A total of 200tomato fruits were randomly purchased from Abraka main, Abraka small, Eku, Obiaruku and Warri markets, Delta State. From each market, 20 fresh and 20 spoilt tomatoes were purchased from 5 sellers. Samples were packaged into sterile containers and transported to the laboratory for analysis. The proximate composition and data analysis were conducted using standardized methods of the Association of Analytical Chemists (AOAC) and analysis of variance (ANOVA). The results revealed the proximate composition varied significantly between fresh and spoilt tomatoes at P<0.05. Fresh tomato had higher levels of carbohydrate, protein, fat, moisture, ash and fibre compared to spoilt tomato fruits. Five (5) genera and six (6) species of fungi were isolated from the damaged tomatoes and characterised culturally including Aspergillus ochraceus, Aspergillus niger Fusarium oxysporum, Rhizopus stolonifer and Saccharomyces cerevisiae, Sclerotinia sclerotiorum, with the most predominant fungus being Saccharomyces cerevisiae (36%). The study emphasizes proper postharvest treatments of tomatoes to prevent nutritional loss and minimize risks associated with spoilage fungi for optimal health benefits.