Nutritional Quality of Chocolate Berry (Vitex payos) Fruit and its Utilization in Yoghurt Production

Abstract

Chocolate berry (Vitex payos) is one of the neglected indigenous fruit trees in tropical Africa. Information on use of its fruits for food is scarce except as a seasonal snack by members of communities in localities where it grows. The bulk of the fruit however goes to waste as a result of post-harvest losses. This study sought to determine the nutritional composition of V. payos fruit and its potential use in production of flavoured yoghurt. Vitex payos fruits were collected from Kitui and Tharaka-Nithi Counties of Kenya. Fruits were pulped and analyzed for nutrients composition, phytochemicals, and antinutrient contents. The fruit pulp was also used in making V. payos fruit flavoured yoghurt with varying concentration of the pulp (i.e., 0%, 5%, 10%, 15%, and 20%) and the products were subjected to physicochemical and sensory analyses. Sensory evaluation was then used to determine the yoghurt sample with the most preferred fruit concentration. The preferred sample was then subjected to shelf-life studies at ambient (25℃) and refrigerated (4℃) storage conditions for six and eighteen days respectively. The result revealed that apart from crude protein, crude fat, sodium, magnesium, zinc and iron contents, significant differences (P<0.05) were observed in all other nutrients (crude fibre, carbohydrates, phosphorous, potassium, calcium, niacin, pyridoxine and ascorbic acid) in fruit samples between the two Counties. Samples from Kitui and Tharaka-Nithi Counties had high crude fiber content of 55.59±5.50 and 42.21±4.62 g/100g-dwb respectively and high potassium content of 2331.60±185.7 and 1816.60±176.2 mg/100g-dwb respectively). All phytochemicals and anti-nutrients were significantly higher (P<0.05) in Kitui than in Tharaka-Nithi County samples. Vitex payos fruit flavoured yoghurt with 5% fruit pulp was the most preferred by panelists and when this sample was subjected to shelf-life studies, it remained acceptable in its physicochemical, sensory and microbial properties under refrigerated storage for eighteen days. However, the product was only safe for human consumption on the initial day of study at ambient conditions since yeast and moulds counts exceeded 100cfu/mL on the third and sixth days of study. This study concluded that V. payos is a good source of nutrients and phytochemicals whose concentration may be region-dependent and can be promoted as an alternative source of nutrients. Based on sensory analysis and shelf-life studies results, this study recommends adoption of V. payos flavoured yoghurt sample with 5% fruit pulp content for commercialization.