© All Rights Reserved *Corresponding author. Email: humahums@yahoo.com International Food Research Journal 26(1): 313 - 318 (February 2019) Journal homepage: http://www.ifrj.upm.edu.my * Bader Ul Ain, H., Saeed, F., Arshad, M.U., Ahmad, N., Niaz, B. and Tufail, T. Institute of Home and Food Sciences, Government College University Faisalabad, Kotwali Rd, Gurunanakpura, Faisalabad, Punjab 38000, Pakistan. Improving the bioactive functionality of barley dietary fbre by chemical treatments in combination with extrusion process Abstract The present work was carried out to observe the comparative efectiveness of diferent chemical treatments in combination with simultaneous thermal treatment on soluble and insoluble dietary fbre ratio to improve functional properties of barley. For this purpose, two varieties of barley i.e., Haider-93 and Jau-87 were assessed for their chemical composition, mineral, non-starch polysaccharides and dietary fbre contents through respective methods. Next, both varieties were chemically treated with acid, alkaline and consecutive acid-alkaline treatments in combination with thermal treatment. Results of chemical composition revealed that Jau-87 was higher in moisture (11.4%), crude fat (2.67%) and crude fbre (4.70%) whereas Haider-93 exhibited higher ash (2.56%) and crude protein content (12.7%). Moreover, barley was rich source of potassium ranging from 4.77-5.07 g/kg. Likewise, main non-starch polysaccharides in barley were arabinoxylan (3.60-3.77%) and β-glucan (3.65-3.67%). Furthermore, barley contained more insoluble dietary fbre (12.00-12.40 g/100 g dm) than soluble dietary fbre (4.73-5.70 g/100 g dm). Additionally, modifcation of soluble (1.48%) and insoluble dietary fbre (8.71%) ratio through extrusion processing was non-signifcant whilst acid-alkaline treatment showed highly signifcant results i.e., 771.46% increase in soluble dietary fbre and 53.39% decrease in insoluble dietary fbre It was therefore concluded that chemical treatments alone or in combination with twin-screw extrusion increased soluble dietary fbre. However, simultaneous efect of acid and alkaline treatment most efectively increased the solubility of barley. Introduction In the past few years, eforts have been aimed to determine the scientifc justifcation for functional properties of dietary fbre (Jha and Berrocose, 2015). Dietary fbre refers to the non-digestible carbohydrate entity which is impervious to enzymatic assimilation and absorption in small intestine of humans. It is conventionally classifed in two categories according to their water solubility: insoluble dietary fbre and soluble dietary fbre (Lattimer and Haub, 2010; Dhingra et al., 2012). Each fraction has its own physiological efects (Fuller et al., 2016). Soluble fractions are fermented faster into short chain fatty acids, and are consumed by the benefcial intestinal bacteria than insoluble fractions. From functional point of view, soluble dietary fbre is more important than insoluble dietary fbre. In this respect, soluble dietary fbre has been found to be signifcant in reducing the high cholesterol, triglyceride and glucose levels in blood through binding. These can also afect the texture, gelling, thickening and emulsifying properties of foods (Anderson, 2009). Approximately 20-35% of soluble dietary fbres and 65-80% of insoluble dietary fbres are present in foods (mainly cereals). As far as the RDA ratio is concerned, one quarter of soluble dietary fbre and three quarters of insoluble dietary fbre (1:3) is recommended (Burton-Freeman et al., 2017). The main sources of dietary fbres are cereals, nuts, fruits and vegetables (Jha and Berrocose, 2015). Barley (Hordeum vulgare L.) is one of the richest sources for fbres among the cereal group, as it contains about 24% dietary fbre in the ratio of 3:2 for insoluble dietary fbre and soluble dietary fbre (Feng et al., 2017). Chemical treatment has been considered as the most important approach among all techniques because chemical reagents cause less damage to the molecular structure of the dietary fbre, and the content of soluble dietary fbre could be increased Keywords Barley Dietary fbre Extrusion Chemical modifcation Article history Received: 10 January, 2018 Received in revised form: 12 July, 2018 Accepted: 11 Augus, 2018