Effects of Leaf Extracts of Selected Plants on Quality of Stored Citrus sinensis (Sweet Orange) Juice

Abstract

Reduction in the quality of fruits during storage has been a concern to the consumers and the effect can be felt on the economy of developing countries. Leaves of plants such as Canna indica, Megaphrynium macrostachyum and Thaumatococcus daniellii have been documented as food packaging materials in West Africa. Based on this, the quality of stored sweet orange juice was investigated using ethanolic extracts of leaves of C. indica, M. macrostachyum and T. daniellii to enhance the shelf life of the juice. The extracts were used to assess the quality of juice for 30 days using quantitative parameters such as total soluble solid, browning potential, pH, microbial analysis and turbidity at 4 oC and at room temperature (27-31 oC). The qualitative and quantitative phytochemical constituents of the extracts were determined. The extracts’ toxicity was determined using Brine shrimp. The quality assessment evidently revealed that the freshly squeezed orange juice with the extracts possess tolerable activity to enhance the shelf life of orange juice. The leaf extract of M. macrostachyum had the highest preservation rate on the juice after 30 days. The qualitative phytochemical screening revealed the presence of alkaloid, tannin, saponins, flavonoids, steroids and terpenoids in the three plants tested. The quantitative phytochemical analysis of the most active extracts in the three plants revealed that M. macrostachum had the highest contents of alkaloids (107.48 mg/g) and flavonoids (56.92 mg/g).The study showed that the extracts were non-lethal on Brine shrimp. This study ascertained the potential preservative qualities of the test plants for enhancing the shelf-life of orange juice.