Twin-Screw Extrusion of Pre-Germinated Brown Rice: Physicochemical Properties and ?-Aminobutyric Acid Content (GABA) of Extruded Snacks

Author(s):  
Nirandorn Chanlat ◽  
Sirichai Songsermpong ◽  
Chulaluck Charunuch ◽  
Onanong Naivikul

Pre-germinated brown rice (PGBR) from non-glutinous (KDML 105) and glutinous (RD 10) varieties was produced by a soaking method in cool water at 25°C for 48 h. After germination, increased crude fiber, reducing sugar (P ? 0.05) and the ?-aminobutyric acid (GABA) content (P ? 0.01) and decreased fat were observed. The extrusion was carried out in a twin-screw extruder by a central composite design (CCD) which studied the effect of feed moisture (15.6-22.3%), screw speed (264-434 rpm) and pre-germinated glutinous brown rice flour level (0-63.6%) on the physicochemical properties of extruded snacks (expansion ratio, density, hardness, brittleness, water absorption index (WAI), water solubility index (WSI)) and GABA content. Second-order polynomial models were computed and used to generate surface plots. Increasing the feed moisture increased the density (P ? 0.01) hardness and WAI, and decreased the expansion ratio, brittleness (P ? 0.01) and WSI (P ? 0.05). Increasing the screw speed increased the expansion ratio, brittleness, WAI and WSI, and decreased the density and hardness. Increasing the levels of pre-germinated glutinous brown rice flour increased the expansion ratio (P ? 0.01), brittleness, WSI (P ? 0.01) and the GABA content (P ? 0.01), and decreased the density, hardness (P ? 0.01) and WAI (P ? 0.01), while the feed moisture content and screw speed had no significant effect on the GABA content (P > 0.05). This knowledge can be used in the design of customer-oriented extruded PGBR products.

2014 ◽  
Vol 10 (3) ◽  
pp. 503-510 ◽  
Author(s):  
Gurkirat Kaur ◽  
Savita Sharma ◽  
Baljit Singh

Abstract Rice flour, wheat flour and flour in combination (rice:wheat::50:50) were used to prepare modified flour using co-rotating twin screw extruder. The effects of barrel temperature, feed moisture and screw speed on product responses (specific mechanical energy[SME], expansion ratio and bulk density) were studied using response surface methodology. Extrusion variables were barrel temperature (125, 150 and 175°C), moisture content (14, 16 and 18%) and screw speed (300, 400 and 500 rpm). Expansion ratio was directly affected by barrel temperature, whereas increase in temperature decreased SME and bulk density. Feed moisture had positive effect on bulk density only, i.e. it increased with increase in moisture. Increase in screw speed was directly related to SME and expansion ratio. The higher R2 values showed that the model developed for the response variables appeared adequate for predictive purposes.


Food Research ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 199-207 ◽  
Author(s):  
I.F. Bolarinwa ◽  
P.T. Lim ◽  
Kharidah Muhammad

Food Research ◽  
2021 ◽  
Vol 5 (S1) ◽  
pp. 94-102
Author(s):  
H.T. Truc ◽  
P.Q. Trung ◽  
N.T.L. Ngoc ◽  
N.D.T. Binh ◽  
L.N.D. Duy ◽  
...  

Roasting temperature and time are important parameters in the process of roasted germinated brown rice flour (RGBRF), which cause the loss of bioactive ingredients and sensory value of the product. During roasting and storage, fat oxidation is also one of the problems that reduce the quality of RGBRF. In order to complete the RGBRF process, experiments using different temperature and time as 160oC, 200oC, 240oC for 10 to 30 mins were done to find the best roasting conditions. To limit the oxidation of fat during the processing and preserving RGBRF, ergothioneine (ERG) extract from enoki mushroom were supplemented at 3%, 5%, 7% and 10% (w/w) before roasted, the product was then ground and put into two types of packaging (PA and aluminum), vacuum seamed and stored at room temperature for 8 weeks were carried out. The results showed that germinated brown rice (GBR) which supplemented 3% of the extract before roasted at 200oC for 30 mins showed the best quality in term of sensory value, γ-aminobutyric acid (GABA) content and helped to limit fat oxidation as well as maintained stable quality after 8 weeks of storage in PA and aluminum packaging. In addition, the results from in vitro of starch resistance and in vivo of sugar absorption capacity in rats showed that RGBRF did not significantly change the GI index as well as the ability to absorb sugar compared to unroasted product. The results indicated that RGBRF should be used as a nutritious food with the ability to supplement bioactive compounds to the people at risk of lifestyle diseases.


2019 ◽  
Vol 57 (3B) ◽  
pp. 116
Author(s):  
Van Anh Luu ◽  
Hang Thanh Nguyen ◽  
Giang Truong Nguyen

ABSTRACT – QMFS 2019Germinated brown rice strains contain more bioactive substances than germinated regular rice ones, however germination conditions play an important role in the activity and the content of those substances. The proper germination process provides the optimized active ingredients from rice that can be used for the production of nutritious beverages. In this study, we investigated the effects of pH, temperature and incubation time in microaerobic culture condition on the change of bioactive substances in AnhDao brown rice. The optimal germination condition with pH at 3, temperature of 35 0C and time for 36h release 109.11U/g of the α-amylase activity, 17.22(U/g) of the enzyme glutamate decacboxylase (GAD), 1.38(U/g) of protease, 231.76mg/100g of GABA content and 21.9 (mgGAE/100g) of polyphenol from germinated AnhDao brown rice. In nutrient evaluation, germinated AnhDao brown rice contains 65.53% of starch, 2.49% of lipid, 9.13%of protein, 2.04% of reducing sugar, and 1.26% of ash.Key words: Germinated brown rice, bioactive substances, α-amylase, protease, glutamate decacboxylase (GAD), Gamma aminobutyric acid (GABA).


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