Effect of extrusion process on antioxidant activity, total phenolics and β‐glucan content of extrudates developed from barley‐fruit and vegetable by‐products

Abstract

The aim of this study was to determine the effects of extrusion processing variables on antioxidant activity (AA), total phenolic content (TP) and b-glucan content (BG) of extrudates. Products were prepared by extrusion cooking of barley flour, barley flour-tomato pomace and barley flour-grape pomace blends. Antioxidant activity as measured by the DPPH method was 43.17 ± 0.362, 27.57 ± 0.120 and 82.23 ± 0.785% while TPs, expressed as ferulic acid equivalents, were 5.29 ± 0.126, 4.66 ± 0.023 and 9.15 ± 0.015 mg g )1 dry sample in the extracts obtained from barley flour, tomato and grape pomaces, respectively. Extrusion cooking decreased AA and TP of barley, barley-tomato pomace and barley-grape pomace extrudates. Temperature and screw speed had significant (P < 0.05) effect on BGs of barley flour and barley-grape pomace extrudates. However, BG of tomato pomace blend extrudates had significantly (P < 0.05) influenced from pomace level only. Results indicated that the content of b-glucan is higher in barley flour than in extrudates of barley flour and pomace blends.

Change in Health Ingredients of Whole Tibetan Hull-Less Barley after Steam Explosion and Simulated DigestionIn vitro

“…Shih et al (2009) investigated the effects of extrusion on the TAC of sweet potato and reported that the scavenging effect on DPPH radicals increased. However, Altan et al (2009) found that the extrusion decreased TAC and TPC of barley, barley-tomato pomace, whereas others reported no effect (Ş ensoy et al 2006;Altan et al 2009). …”

Dynamics of rapid starch gelatinization and total phenolic thermomechanical destruction moderated via rice bio-extrusion with alpha-amylase activation

“…22 Nevertheless, the relative superiority of extrusion is not obvious as many authors have still found a great loss (more than 50%) of phenolics during extrusion. 20,23,24 This dilemma was somewhat reversed when the thermostable a-amylase was introduced into cereal extrusion (mainly to achieve a high degree of starch gelatinization and liquefaction in the industries of starch saccharication, cake making, ethanol fermentation and liquor brewing) because the phenolics seem to be indirectly protected both in free and bound forms. 3,19,25,26 The mechanism of rapid starch gelatinization coupled with total phenolic retention during bioextrusion is still ambiguous, in spite of the otherwise complex impact of extrusion processing (without an enzyme catalyst) on the chemical and antioxidative prole, considering the multiple operating factors of temperature, moisture content, shear force, local friction and mechanical energy.…”

“…The enzymatic hydrolysis of rice starch was well conducted as lower DP (<0.1 Mpa) and SME (94.5-181 kJ kg À1 ) were tested for enzymatic extrusion (Table 1). Furthermore, the k G values of both TE and EE had a positive relation to N ( 20 and other mixtures of cereal ours. 42 We also found that enzyme addition did not change but deepened the negative connection between c/c 0 and N (Fig.…”

“…16,17 However, mankind does not always accept the over-processing of edible sources due to the avoidance of the thermal and mechanical impact on those trace nutritional or functional substances (e.g., polyphenols, avonoids, vitamins) that are vulnerable to loss. [18][19][20] In recent years, consumer demand for extruded food products that are rich in bioactive compounds has gradually been increasing in consideration of the short-time processing time which is characteristic of extrusion, giving a potential advantage for retaining phenolics compared to other heating treatments such as boiling, blanching and evaporation which oen require heating for several hours. 18,21 These foods are mostly made from cereals or plants with abundant starch and phenolic compounds, which have great relevance for human nutrition and health attributed to their diverse bioactivities of antioxidation, anti-inammation, anti-proliferation and modulation of signal transduction.…”

Use of Red Cactus Pear (Opuntia ficus-indica) Encapsulated Powder to Pigment Extruded Cereal

“…Studies have demonstrated that additives used as powders, extracts, concentrates, or byproducts from different sources can substantially change the food's physical characteristics and thus potentially affect its acceptability. Such characteristics include water absorption index, bulk density, water solubility index, expansion index, texture, and color [14][15][16][17]. The aim of the present study was to evaluate the changes in these physicochemical properties following the addition of 2.5, 5.0, and 7.5% (w/w) red cactus pear encapsulated powder to pigment extruded cereal.…”