IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) e-ISSN: 2319-2402,p- ISSN: 2319-2399.Volume 11, Issue 1 Ver. I (Jan. 2017), PP 36-40 www.iosrjournals.org DOI: 10.9790/2402-1101013640 www.iosrjournals.org 36 | Page Changes in Postharvest Qualities of Stored Fresh Maize (Zea Mays L.) at Tropical Ambient Condition I. B. Oluwalana 1 , M. O. Oluwamukomi 1 , A. A. Badejo 1 and F. A. Bello 2 1( Department of Food Science and Technology, Federal University of Technology Akure, Nigeria) 2( Department of Food Science and Technology, University of Uyo, Uyo, Nigeria) Abstract: The effect of passive modified atmosphere packaging on some postharvest qualities of stored fresh maize was investigated at tropical ambient temperature (28±2 °C) and 80% RH. Changes in the appearances of husk, silk and kernel, kernel firmness, weight and microbial growth were monitored. Freshly harvested yellow maize (FHYM) served as control. Results showed that packaging film greatly affected the appearances of the husk, silk, kernel and kernel firmness compare to the control sample. The highest weight loss was observed in dehusked maize while the maize samples in packaging film had the least weight loss. Lactobacillus sp., Micrococcus liteus, Streptococcus sp., Serratia marcescens, Bacillus sp. and Saccharomyces cerevisiae were the bacteria isolated from the stored fresh maize while the suspected fungal include Rhizopus stolonifer, Penicillium notatum and Fusarium sp. Higher bacteria counts were observed in samples packaged with 25 and 30 μm LDPE while the least was found in unpackaged undehusked maize. The current packaging conditions had no impact on the shelf life of fresh maize. Keywords: Appearances, Fresh maize, Microorganisms, Modified atmosphere packaging, Weight loss I. Introduction Quality is generally defined as all those characteristics of a food that lead a consumer to be satisfied with the product and it is the main objective of postharvest technology [1]. Assessment of postharvest shelf-life of fresh-cut or minimally processed packaged fruit and vegetables is often based on changes or stability in physical attributes such as colour, firmness and absence of decay. These attributes reflect visual acceptance associated with produce quality. The modified atmosphere packaging technique consists of the enclosure of respiring produce in polymeric films in which the gaseous environment is actively or passively altered to slow respiration, reduce moisture loss and decay and/or extend the shelf life of the products [2] Maize also known as corn (Zea mays) is a cereal crop which ranks among the most essential crops in the world agricultural economy [3]. It is agronomically versatile and become one of important staple food crops for most part of the population of Africa [4]. Fresh maize kernels are rich source of vitamin C, E, K and B- group. Potassium is a major mineral present which has a good significance in human diet [5]. It is a relatively poor cereal when it comes to the quality of its protein, because it has limiting amounts of two essential amino acids, lysine and tryptophan [6]. Although hundred of maize cultivars exist only limited varieties are commercially grown for human consumption and they include dent corn, flint corn, popcorn, waxy corn and sweet maize [7]. Agricultural commodity is a perishable food crop due to the presence of high moisture content [8]. Fresh maize is prone to fast post-harvest deterioration leading to kernel desiccation, loss of sweetness and moisture, husk discoloration and development of pathogens as a result of metabolic reactions [9]. Due to its perishable nature, it has to be consumed immediately after harvest by boiling or roasting. [10] reported that wrapping or sealing a fresh produce with a suitable plastic film reduce moisture loss by creating modified atmosphere around the fruit thereby retarding respiration. The present work was undertaken to test the effectiveness of passive modified atmosphere packaging on the extension of shelf life of fresh maize at tropical ambient temperature. II. Materials and Methods Ears of fresh yellow maize on the cob (SUWAN 1-SR) was obtained from the Teaching and Research farm of the Federal University of Technology Akure (FUTA). The two different packaging materials used were 25 and 30 μm gauges of low density polyethylene (LDPE) with 34 cm × 14.5 cm in area (TUBI Investment Ltd, Akure, Nigeria). Fresh maize were grouped into six lots: undehusked maize (T1), dehusked maize (T2), undehusked maize packaged with 25 μm LDPE (T3), dehusked maize packaged with 25 μm LDPE (T4), undehusked maize packaged with 30 μm LDPE (T5) and dehusked maize packaged with 30 μm LDPE (T6). Freshly harvested yellow maize (FHYM) was harvested daily for comparison purpose and was used as the control sample. The fresh maize was placed singly in LDPE and sealed properly using an impulse sealer (MEC, China). Samples were then transferred into a chamber set at temperature of 28±2 o C and 80% RH maintained for 8 days.