S. M. M. Kabir*
Department of Chemistry, Rajshahi University of Engineering and Technology, Rajshahi, Bangladesh
A. Alam
Department of Chemistry, Rajshahi University of Engineering and Technology, Rajshahi, Bangladesh
B. Uddin
Department of Food Technology and Rural Industries, Bangladesh Agricultural University, Mymensingh-2202
Antioxidant; Shelf-life; Mango varieties
Department of Chemistry, Rajshahi University of Engineering and Technology, Rajshahi, Bangladesh
Quality and Nutrition
Samples of mango in three varieties like gutti, asina, langda are collected from various area of the country like southern part of country named Jessore, Northern part named Chapinawabgoanj, Eastern side of Bangladesh named Chittagong. All mangoes were mature and ripe. Average weights of the experimental mangoes were 180g -200g of gutti, 300g-350g of asina and 190g-250g of langda. All were checked visually and only defect free mangoes were allowed for study. Two products, dehydrated product named mango bar and mango fruit drink were considered to experiment. Sample preparation (mango pulp) Mangoes were washed by treated water, initially normal and finally hot water (450C). After peeling and deseeding the mangoes of three varieties (gutti, asina, and langda), these were kept in separate stainless steel vessel with covers. Then they were transferred into refiner having mesh-350 one by one to remove fibers from the mango pulp. Right after samples were transferred in the steam jacket kettle and heated to 950C-1000C for 30 minutes to pasteurize the samples. Finally pulps were filled into screw cap bottles sealed and stored at room temperature for further use. Now some parameters like vitamin A, beta carotene, vitamin C, colour, and flavor are tested on these three separate mango pulps of gutti, asina and langda variety. Sample preparation of mango bar The prepared stocks of mango pulp of the three varieties was heated up to obtain the 0brix 280 and poured by 4kg in each tray into the three separate SS-trays. All trays were cleaned and greased by applying food grade paraffin oil on the surface of the trays. Then the trays with mango pulps of gutti, asina and langda were transferred into a drier for drying by 550C-600C for 48 hours and completion of dehydrating the first layer of the bar then again 4kg of mango pulps of the experimental three varieties were poured on the trays and dried by using same temperature (550C-600C) and time (48 hours) in the same drier for drying the second layer. After completion of drying the two layers of those products of three varieties were turned into one layer. Now they were sliced by SS-knife having size of length 8.0 cm, width 2.0 cm and thickness 0.45 cm and again the slices of the mango bars were dried for further 24 hours in the drier till achieving the moisture 15%. The prepared sliced bars were packed in the layered flexible foil which was made of PET (polyethylene terothalate), MPET (metalize polyethylene terothalate) and LLDPE (Linear low density polyethylene) and kept in an ambient temperature for further various experiments. Samples were analyzed for microbial loads at o, 30, 60, 90, 150, 180, 240 and 270 days. Sample preparation of mango fruit drink Mango pulp of three varieties like gutti, asina and langda were taken from stock and refined by refiner with mesh-350 separately to remove fibers and other foreign particles and preserved in three separate master vessel. In another three separate SS-vessel, juice ingredients like citric acid 4.94%, sugar as syrup13%, mango emulsion 0.015%, mango flavor 0.045%, mango pulp 10% and water 72% were taken and blended for 30 minutes. Then the blended fruit drinks were transferred into three separate saucepans and heated them at 850C-900C for sterility the fruit drinks and filled in the cleaned and washed PET (polyethylene terrothalate) bottles and closed the filled bottles with plastic closures and kept in an ambient temperature for further study. Apparatus for analysis of vitamin A, beta-carotene and vitamin C For chemical test: Liquid Chromatography Mass Spectrometer (LCMS) (model no: LCMS-8040, origin: Shimadzu, Japan); Balance (model no: BSA 124S, origin: Sartorius scientific instruments (Beijing) Co, Ltd, China). Test parameters (vitamin A, Beta carotene and vitamin C) were tested by method AOAC. Microbial parameters as coliform, TPC, Yeast and Mold are tested. Eosin methyl blue (EMB) agar and MacConkey broth w/neutral red (HiMedia Laboratories Pvt. Ltd., India) for coliform; Plate count agar (HiMedia Laboratories Pvt. Ltd., India) for TPC; Potato dextrose agar (HiMedia Laboratories Pvt. Ltd., India) for yeast & mold testing. Methyl Red Indicator; Iodin; Methyl Orange; Ferroin Indicator Sol; Glycerol; Methylene Blue; Oil emersion; Chrystal violet; Safranin; Covacs Indole reagent; Vogusproscure; MIU Medium; Lactophenol cotton blue; Microbial testing of parameters (Coliform, TPC, yeast and mould) were tested by using the method BDS ISO 4832:2009, BDS ISO 4833:2009 and ISO 21527-1: 2008 consecutively. Statistical analysis All the experiments were carried out triplicates. The experimental data were compiled, tabulated and analyzed. Data analysis was carried out using commercial statistical software Stat graphics Centurial XVI.
Bangladesh J. Sci. Ind. Res. 52(4), 303-308, 2017
Journal