Physicochemical and antioxidant properties of selected Philippine indigenous berries

Abstract

There are many underutilized berries indigenous to the Philippines with various chemical and nutritional properties that are yet to be explored and up to date, studies on these are still limited. Among which are locally known as bignay (Antidesma bunius (Linn.) Spreng.), duhat (Syzygium cumini (L.) Skeels), and lipote (Syzygium spolycephaloides (C.B. Rob.) Merr.). Hence, to gain more understanding on the potential of the selected Philippine indigenous berries as functional food, analyses of some of their physicochemical and antioxidant properties were undertaken. The results from this investigation can serve as baseline data to support functional food product/nutraceutical development and/or in vitro and in vivo studies and promote the utilization of these Philippine indigenous berries. The primary objective of this study was to evaluate some physicochemical properties, including color, pH, water activity, total soluble solids, total sugars, proximate composition, as well as antioxidant properties such as antioxidant activity, total phenolic content, and total flavonoid content of the selected Philippine indigenous berries, bignay “kalabaw”, bignay “common”, duhat, and lipote. The physicochemical properties were evaluated using a chromameter for color values, pH pen for pH values, water activity meter for water activity, refractometer for total soluble solids, phenol-sulfuric acid method for total sugars, and AOAC international guidelines were followed for the proximate analysis. For the antioxidant properties, antioxidant activity was determined through DPPH free radical scavenging activity and TEAC -ABTS assays while the total phenolic and total flavonoid contents were analyzed using the Folin-Ciocalteu method and aluminum chloride colorimetric assay, respectively. Results of the present study showed that the selected Philippine indigenous berries, bignay cultivars, “kalabaw” and “common”, duhat, and lipote, are good sources of energy and have significant levels of macronutrients such as from fat, protein, and carbohydrate as well as phenolic compounds as compared to other varieties of berries that are widely grown across many other countries. Each Philippine indigenous berry evaluated in the present study has its own unique characteristics and advantage, especially when it comes to the antioxidant properties. Hence, the selected Philippine indigenous berries are another good source of natural antioxidants with various significant health benefits and high value for commercialization and as functional food. The results warrant further in vitro and/or in vivo tests of these berries’ functional properties and its health and nutritional benefits.