Characteristics of Onion under Different Process Pretreatments and Different Drying Conditions
- *Corresponding Author:
- Alabi KP
Lecturer II, Department of Food
Agriculture and Bio-Engineering
College of Engineering and Technology
Kwara State University
Kwara State, Nigeria
Received Date: December 14, 2015; Accepted Date: January 05, 2016; Published Date: January 14, 2016
Citation: Alabi KP, Olaniyan AM, Odewole MM (2016) Characteristics of Onion under Different Process Pretreatments and Different Drying Conditions. J Food Process Technol 7:555. doi:10.4172/2157-7110.1000555
Copyright: © 2016 Alabi KP, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Introduction: Onion (Allium cepa) is an important spice crop often grown outdoors in temperate climates as an annual crop because of its adaptability to varying weather conditions. It is an underground vegetable which varies in size colour, firmness and strength of flavour. Onion is often called “poor man’s orange” because it is a good source of vitamins, particularly Vitamin A and C. It is also a rich source of minerals such as iron, thiamine, niacin and manganese contents. Onion is said to be very useful against heart diseases and many bacterial species including bacillus subtilis, salmoneva, and E. coli. This vegetable crop is highly perishable in its natural state after harvest resulting in huge postharvest losses during storage, transportation and marketing in the production season and extreme scarcity in the off-season which can be checked by drying.
Material and methods: The main materials used were 192 samples of pre-treatment and 10 samples of untreated (control) fresh onion. Others equipments used were temperature controlled dryer, sensitive weighing balance, water baths (Shell Lab Model and HH-W420, XMTD-204 Model), thermo-hygrometer, desiccators, desiccants, stop watch, onion slicer, stainless tray, foil wrap, conical flask, measuring cylinder, NaCl and distil water. Agarry and AOAC methods were used for quantitative analysis and nutritional analysis respectively. Statistical analysis of all data obtained was done.
Results: Results showed that drying rate, water loss, solid gain, vitamin C, manganese and iron contents varied with different levels of OSC, OPD and OST at p ≤ 0.05. However, drying rate, water loss, solid gain and all the quality parameters were influenced by all the process parameters.
OSC = Osmotic solution concentration
OST = Osmotic solution temperature
OPD = Osmotic process duration
Conclusion: Osmotic dehydration pretreatments had significant effect on process outputs (drying rate, water loss, solid gain, vitamin C, manganese and iron contents of onion.