Journal of Food and Nutrition Sciences 2014; 2(5): 220-226 Published online September 20, 2014 (http://www.sciencepublishinggroup.com/j/jfns) doi: 10.11648/j.jfns.20140205.13 ISSN: 2330-7285 (Print); ISSN: 2330-7293 (Online) Post harvest physicochemical properties of soursop (Annona muricata L.) fruits of Coast region, Tanzania Othman Chande Othman 1, * , Christina Fabian 2 , Esther Lugwisha 1 1 University of Dar es Salaam, Chemistry Department, P. O. Box 35061, Dar es Salaam, Tanzania 2 Mkwawa University College of Education, Chemistry Department, P.O. Box Private Bag, Iringa, Tanzania Email address: o_chande@yahoo.co.uk (Othman O. C.), tina84f@yahoo.com (Fabian C.), elugwisha@gmail.com (Lugwisha E.) To cite this article: Othman Chande Othman, Christina Fabian, Esther Lugwisha. Post Harvest Physicochemical Properties of Soursop (Annona Muricata L.) Fruits of Coast Region, Tanzania. Journal of Food and Nutrition Sciences. Vol. 2, No. 5, 2014, pp. 220-226. doi: 10.11648/j.jfns.20140205.13 Abstract: The physicochemical composition of harvested soursop (Annona muricata L.) fruits from Coast region, Tanzania, during open-air storage was determined. The ash, titratable acidity, crude fat, crude fiber, moisture and sugars content were determined by proximate analysis. Ascorbic acid contents were determined using the 2,6-dichlorophenol-indophenol dye method while macro-nutrients and heavy metals were determined by Flame Atomic Absorption Spectrophotometry (FAAS). The fruits were harvested at the mature ripe stage and kept in open air storage over several days. The determinations were done immediately after fruit arrival at the laboratory and thereafter at intervals of two days from the day of harvest. The results showed that soursop fruits had high moisture content (73.1% – 82.1%), low titratable acidity (0.10 – 1.25% ca), low crude fat (0.42 mg/100 g-fw), moderate ash content (0.87 mg/100 g-fw) and crude fibre content (6.09 mg/100 g-fw), high ascorbic acid content (34.0 – 19.7 mg/100 g-fw), high total sugars content (34.3% – 45.3%), reducing sugar content (18.9% – 39.2%) and sucrose content (15.5% – 30.0%). Of the macroelements Na, Ca and K, the average content were 895.6, 870.3 and 367.5 mg/100 g-fw respectively. Heavy metals (Fe, Zn, Cu, Pb and Cd) content was very low in the soursop fruits, ranging between <0.0015 mg/100 g-fw for Cd and 0.82 mg/100 g-fw for Fe. During storage, the moisture content, titratable acidity level and sugars content in the fruit were all increasing whereas the ascorbic acid content was decreasing. There were no significant changes during storage for levels of crude fat, fiber, ash, mineral elements and heavy metals. The findings from this study suggest that this fruit from coast region of Tanzania can contribute nutritionally to the health of the consumer. Keywords: Soursop, Annona Muricata, Physicochemical, Proximate Analysis, Storage, Macronutrients, AAS, Post-Harvest, Tanzania 1. Introduction Information on the nutrient composition of locally available foods especially fruits is of immense importance because of the need to supply foods according to their nutritive values to the people. Dietary supplements are now made using different fruits, vegetables and also herbs in order to provide natural curative as well as preventive methods for combating diseases and poor health. For Tanzania, as it is for other developing countries, there exists very limited information on the nutritive value of its many natural foods especially it’s wild and underutilized fruits so that these may be utilized for such purposes. Soursop (Annona muricata L.) fruits are important fruits as they are not only a good source of vitamins, dietary fiber and minerals and provide flavor, aroma and texture to the pleasures of eating food but also are claimed have anticancer and antioxidant capabilities [1]. Studies [2, 3] suggest that compounds from soursop tested on breast cancer cells in culture were more effective than chemotherapy in destroying these cells. The soursop fruits are normally eaten fresh or as fresh soursop juice. There is growing interest in this fruit because it is considered to be a functional product of great benefit to the human diet as it contains several groups of substances that have anti-cancer and antioxidant properties that are useful in disease risk reduction. The soursop fruit and fruit juice are taken as medicine for worms and parasites, to