Studies on Nutritional Composition and Efficacy of Selected Spices in Southern Nigeria against Some Food Spoilage Fungi

Abstract

The efficacy of antifungal property of aqueous and ethanolic extracts of Alligator pepper (Aframomum melegueta), Aidan fruit (Tetrapleura tetraptera) and Black pepper (Piper nigrum) was tested against three fungal isolates implicated in food spoilage. The fungal isolates from stale bread, beans and spoilt onion are Aspergillus sp., Mucor sp. and Penicillium sp. Nutritional composition and antifungal efficacy of the spices was determined using conventional methods and poisoned food technique, respectively. Results obtained showed that the moisture content of the tested spices is low but they are all rich in carbohydrate. Fat content (12.70%), protein content (11.70%), carbohydrate content (62.94%) and energy value (372.20 Kcal) of Alligator pepper is higher and its fibre content is lower than that of the other two spices. Protein content (0.5%) of Black pepper is the lowest among the spices, but on the contrary in terms of ash content. Based on statistical analysis, the spices were significantly different at <0.05 probability. In terms of clear zone of inhibition, ethanolic extract of the three spices had more antifungal effect compared with the aqueous extract whereas the antifungal efficacy of the extracts increased with the increase in concentration. The highest mycelia growth inhibition (4.67 mm) was recorded by ethanolic extract (1.0%) of Aidan fruit tested against Mucor sp. Based on these findings, ethanolic extracts from the selected spices could be used as an alternative to chemical preservatives to prolong shelf life of foods.