Effect of germination temperature on hierarchical structures of starch from brown rice and their relation to pasting properties

2020 ◽  
Vol 147 ◽  
pp. 965-972
Author(s):  
Hongwei Wang ◽  
Naiyong Xiao ◽  
Jiangtao Ding ◽  
Yanyan Zhang ◽  
Xingli Liu ◽  
...  
2016 ◽  
Vol 6 (8) ◽  
pp. 506 ◽  
Author(s):  
Madan Kumar Chapagai ◽  
Nordiana Abu Bakar ◽  
Rohana Abdul Jalil ◽  
Wan Abdul Manan Wan Muda ◽  
Taewee Karrila ◽  
...  

Background: The prevalence of diabetes has increased dramatically in recent decades in the regions where people excessively consume white rice. In spite of the higher nutritional values and bioactive components, only the low to medium glycaemic index (GI) brown rice could be of interests as an alternative to white rice in these regions.  Methods: Five varieties, Chiang (CH), Sungyod (SY), Lepnok (LP) from Thailand and Long grain specialty 1 (LS1) and Long grain specialty 2 (LS2)  from Malaysia were tested for GI. Ten test foods were prepared from 5 varieties by 2 cooking techniques (pressure cooker, PC and rice cooker, RC). Overnight fasted healthy subjects were fed with 25 g glucose as a reference food (RF) on 3 occasions and amount equivalent to 25 g available carbohydrate portion of test food (TF) on 1 occasion in separate days. Fasting and post-prandial capillary blood glucose was measured via finger-prick methods at 0, 15, 30, 45, 60, 90 and 120 min, and the incremental area under curve (iAUC) was determined. The GI of each TF was calculated as percentage of incremental area under curve (iAUC) of TF over RF.Results: The mean GI values of SY (72 – 81, high), CH and LP (59 – 65, medium) and LS1 and LS2 (64 – 73, medium to high) were found due to cooking by PC and RC methods. The GI did not vary significantly (p>0.05) among varieties as well as between cooking methods. GI showed a significant negative correlation with the amylose content (r = –0.70, p<0.05) and significant positive correlation with cold peak viscosity (r = 0.80, p<0.01).Conclusions: All five varieties by either cooking methods are classified as medium to high GI. Medium GI varieties could have potential of being used in diabetic diet. Cooking methods did not significantly alter the glycaemic characteristics of the studied varieties. Amylose content and pasting properties can be used for predicting GI of brown rice. It is urgent to explore low GI brown rice varieties in these regions.    


2021 ◽  
Author(s):  
A. Singh ◽  
S. Sharma ◽  
A. Gupta ◽  
B. Singh

AbstractBrown rice was germinated for different times (12, 24, 36, and 48 h) at different temperatures (25, 30, and 35 °C) with the aim to improve the in vitro digestibility and antioxidant potential of the flour made from it. Results showed that increase in germination time and temperature increased in vitro digestibility of starch and protein during germination of brown rice owing to depolymerisation of starch and protein molecules by enzymatic activity. After germination under varying conditions, antioxidant activity increased from 50.19 to 95.58%, total phenolic and flavonoid contents from 0.88 to 2.02 mg GAE/g and 34.06–62.94 mg QE/100g, respectively. Germination at elevated temperature (35 °C) for prolonged time (48 h) also increased the reducing power by 60.49% and metal chelating activity by 114.50% as a result of structural breakdown of bound phenolics. Increased activity of hydrolytic enzymes with progress in the germination time and temperature also results in continuous reduction in the pasting properties and lightness values (L), while increasing a* and b* values of the flour of germinated brown rice. Tailored germination, therefore, can be offered as a tool to increase nutrient digestibility and bioactive potential of brown rice as compared to non-germinated brown rice, thus, producing naturally modified flour with enhanced functionality.


2015 ◽  
Vol 11 (4) ◽  
pp. 563-571 ◽  
Author(s):  
Shabir Ahmad Mir ◽  
Sowriappan John Don Bosco ◽  
Manzoor Ahmad Shah ◽  
Mohammad Maqbool Mir ◽  
Kappat Valiyapeediyekkal Sunooj

Abstract Brown rice was exposed to 60Co source at 0, 2, 4, 6, 8 or 10 kGy doses and the effect of gamma irradiation treatment on physicochemical properties were investigated. L* value of brown rice was decreased with increase of irradiation dose, whereas a* and b* values increased. The results showed the decrease of kernel hardness, amylose content and pasting properties considerably with irradiation treatment. A-type diffraction pattern was observed in non-irradiated and irradiated rice samples and crystallinity was decreased with irradiation dose. Raman spectrometry showed the decrease of Raman band intensity at higher irradiation doses. Thermal properties of rice samples were decreased slightly after irradiation treatment. Pearson’s correlation studies revealed that irradiation dose was positively correlated with b* value and negatively correlated with amylose content and pasting properties.


2017 ◽  
Vol 24 (4) ◽  
pp. 491-496
Author(s):  
Induck Choi ◽  
Jieun Kwak ◽  
Mi-Ra Yoon ◽  
Areum Chun ◽  
Dong-Soo Choi

LWT ◽  
2020 ◽  
Vol 130 ◽  
pp. 109623 ◽  
Author(s):  
Qingqing Liu ◽  
Qi Kong ◽  
Xingluo Li ◽  
Junfan Lin ◽  
Hao Chen ◽  
...  

2020 ◽  
Author(s):  
Hadi Munarko ◽  
Azis Boing Sitanggang ◽  
Feri Kusnandar ◽  
Slamet Budijanto

Abstract BackgroundGermination can improve the palatability and alter physicochemical, nutritional, and nutraceutical value of brown rice. This study aimed to evaluate the antioxidant, bioactive compounds, fatty acids, and pasting profiles from six Indonesian brown rice varieties during germination. The germination was carried out through a complete soaking method for up to 120 h, and the samples were taken every 24 h germination. ResultsThe results showed that germination increased GABA content in brown rice. The highest level of GABA, up to 126.55 mg/100g, obtained in rice var. Inpari 43, after 120 h. Germination also affected the phenolic content, antioxidant capacity, and γ-oryzanol content, but no consistent trends were observed among the varieties. Fatty acid compositions of germinated brown rice showed no changes during germination. The pasting properties of samples changed significantly after germination, especially in peak viscosity, final viscosity, breakdown, and setback value. ConclusionIn conclusion, the changes in brown rice characteristics during germination, especially for increased GABA content and shifting of pasting properties, are valuable information for developing functional rice-based food products.


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