Original Article Effects of Leaf Extracts of Selected Plants on Quality of Stored Citrus sinensis (Sweet Orange) Juice Oluwagbenga O. ADEOGUN*, Adedotun A. ADEKUNLE, Erute M. ADONGBEDE University of Lagos Akoka, Faculty of Science, Department of Botany, Lagos state, Nigeria; adeogunoluwagbenga@gmail.com (*corresponding author); aaded63@yahoo.com; erute70@yahoo.com 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 o C and at room temperature (27-31 o C). 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. Keywords: leaf, orange juice, plant extracts, quality, shelf life Available online: www.notulaebiologicae.ro Print ISSN 2067-3205; Electronic 2067-3264 Not Sci Biol, 2017, 9(2):256-262. DOI: 10.15835/nsb9210067 Introduction Citrus sinensis is a member of the Citrus family, along with mandarins (tangerines), lemons, limes and grapefruit (Etebu and Nwauzoma, 2014). The fruit of Citrus sinensis forms a significant part of human diet and is usually regarded as a good source of food (Etebu and Nwauzoma, 2014). The fruits, which are the succulent part of Citrus sinensis are characterized by a sweet or acid taste and distinct flavour. The juice, which is directly extracted from the fruits of C. sinensis is of high nutritional value and of significant contribution to the health of humans (Bevilacqua et al., 2011). Food products which are perishable, once introduced into the market, requires protection against spoilage during storage and distribution (Bhat et al., 2012). The longevity and extension of the shelf life of food involves the need to make it to be stable and safe for consumption through preservation (Brul and Coote, 1999; Adegunloye et al., 2006). The reduction in quality of food might be ascribed to the activities of microorganisms. Preservation is a process by which enhancing agents are used to keep food from deteriorating. This enables the food to retain freshness, texture, colour, nutritional value and flavour (Gould, 1999). Microbial spoilage of food decreases the shelf life of the food, which may result in substantial economic losses and potential health hazards to the consumers (Grillo and Lawal, 2010). During production of food, it is crucial that proper measures are taken to ensure safety and stability of the product during its whole shelf-life (Brul and Coote, 1999). Food preservation is becoming an increasing issue to the survival and well-being of humans. The essence of preservation, which can be attached to food safety, is evidenced by the consumer preference for naturally Received: 30 Mar 2017. Received in revised form: 08 May 2017. Accepted: 29 May 2017. Published online: 30 Jun 2017.