In vitro digestibility and physicochemical properties of milled rice (original) (raw)
Related papers
Carbohydrate Polymers, 2011
Digestibility of starches in four rice samples with amylose content (AC) from 1.7 to 55.4%, including a newly developed high-amylose rice, was investigated. An in vitro enzymatic starch digestion method and an AOAC method were applied to correlate rapidly digestible starch (RDS), slowly digestible starch (SDS), resistant starch (RS), and total dietary fiber (TDF) content with the AC in the samples. SDS content decreased and RS and TDF content increased with the increase in AC. The low-amylose rice (AC = 16.1%) had starch granules with weak crystalline structure and was lower in RS and TDF content even though it had a higher AC compared to waxy rice. The digestibility of the starches was not correlated with granule size or degree of crystallinity. The newly developed high-amylose rice starch exhibited a predominant B-type X-ray diffraction pattern, a great proportion of long chains in amylopectin, high gelatinization temperature, and semi-compound starch granules which are attributed to its increased resistance to enzyme digestion.
2015
The effect of gelatinization degree during cooking on the digestibility of cooked rice was investigated through a simulated gastro-intestinal in vitro digestion technique. The changes in starch hydrolysis percentage during simulated digestion were evaluated as a cooked rice digestibility in this study. Polished medium, non-waxy rice grain was soaked into boiling water as a model cooking. The boiling time was set at 10 and 20 min to obtain two gelatinized degree samples. Slurry samples were prepared from the grain samples to examine the impact of structural change of rice grain. The kinetics of cooked rice digestibility showed that there was no significant difference in the equilibrium starch hydrolysis percentage between the grain boiled for 10 min as a partially gelatinized sample and the grain boiled for 20 min as a completely gelatinized sample. However, the large difference between raw and boiled samples was shown. It was also shown that the equilibrium percentage of slurry was ...
2017
In vitro digestibility was used to analyze the glucose content versus the definite digestion time by simulating the starch metabolic pathway in human. Three types of starch were classified as its in vitro digestion rate: rapidly digestible starch, RDS, slowly digestible starch, SDS, and resistant starch, RS. Starch with higher RS content has more dietary fiber, hypoglycaemic effect and reduces cholesterol. High RS and SDS in starch contribute low glycemic index (GI). Enzymatic modification is one of the methods for increasing RS and lowering GI in starch. In this work, four rice flours of one glutinous rice (RD6) and three non glutinous rice flours (Jasmine 105, Pathumthani and Suphanburi rices) were studied with two combinations of enzymatic modification (pullulanase and isoamylase from Psedomonas sp. (PII), pullulanase and isoamylase from Thermus filiformis (PI2). The In vitro digestibility result showed that both enzymatic combinations increased the RS, which caused GI of the mod...
International Journal of Food Properties, 2014
Grain quality attribute tests based on physicochemical, textural, pasting, and in vitro digestion properties of eight different rice cultivars were studied. Basmati varieties showed higher values of amylose content, iodine absorption, blue value, hardness, cohesiveness, pasting temperature, and set back, whereas swelling power, solubility, adhesiveness, peak viscosity, and breakdown values were found to be higher in non-basmati varieties. The release of maltose from basmati rice flour (23.12-25.86 mg/g rice flour) was found to be slower as compared to non-basmati ones (27.43-28.36 mg/g rice flour). Amylose content showed significant correlations with different quality parameters at 5% level of significance.
International Journal of Food Science & Technology, 2019
Gelatinization, pasting, digestibility and estimated glycaemic index of six high amylose rice varieties differing in length/width ratio were studied. Amylose content ranged narrowly (27.8-29.1%). Resistant starch content ranged from 0.44% to 1.4%. In contrast to gelatinisation enthalpy, gelatinisation temperature (GT) ranged narrowly (76.7-77.4°C). For all rice varieties, melting temperature of amylose-lipid complex I and II was around 99°C and 110°C, respectively. The enthalpy of amylose-lipid complex I and II ranged between 0.18-0.87 and 0.23-0.55, respectively. Expected in vitro glycaemic index (GI) of all tested varieties was similar (88.2-92.4). The results showed that the size of the rice grain (length/width) and resistant starch content had no apparent impact on the GI of high amylose rice. The dominant factors determining the digestibility and glycaemic response of the tested high amylose rice varieties seemed to be amylose content and the GT. Besides the pasting temperature, other pasting properties varied significantly but were not correlated to starch digestibility and estimated GI among the six rice varieties. Thus, RVA pasting properties, except for pasting temperature, may not be good predictors for the GI of these high amylose rice.
Intrinsic and extrinsic factors affecting rice starch digestibility
Trends in Food Science & Technology, 2019
Background: The current incidence of obesity and type 2 diabetes is at global epidemic levels. To mitigate their impact, there is a need to develop starch-containing foods that give rise to a low and stable postprandial blood glucose response by increasing the proportion of slowly-digestible and indigestible carbohydrate content. Rice is an ideal target food for such dietary intervention because it is a staple food for over half the world's population. Scope and approach: The starch digestion of cooked white rice grains is usually complete or near complete upon consumption, but the rate of digestion is influenced by intrinsic food properties and extrinsic influences. This review provides an overview of the complex interplay between the starch granule and its interaction with non-starch components of the rice grain (intrinsic characteristics) as well as the effects of processing (extrinsic factors) on starch digestibility. Key findings and conclusions: The intrinsic properties of white rice grains play a significant role in starch digestibility which can be further enhanced after processing, especially by gelatinisation and retrogradation. Post-harvest storage conditions of rice were found to influence starch digestibility but this effect was temperature-dependent. Limited studies investigated starch-lipid and starch-protein interactions in rice, but changes to substrate accessibility have been implicated. Improving our understanding of the effects of processing on starch digestibility can provide an effective tool for food manufacturers to regulate starch digestibility of existing rice varieties.
Journal of Food Science and Technology, 2019
Starch is the main sugar source present in staple foods. Understanding starch hydrolysis during digestion and the resulting glucose release can be important to strategically modulate starch digestion and glucose absorption. In vitro digestion methodologies are fundamental to evaluate starch hydrolysis length and rate, but the lack of uniformity between protocols prevent the comparison of results. In this context, three different Carolino rice varieties (i.e., Carolino white-Cw, Carolino brown-Cb and Carolino Ariete brown-CAb) were submitted to the INFOGEST harmonized in vitro digestion protocol for the evaluation of starch hydrolysis and subsequent glycemic index (GI) determination, and starch granules morphological study. Samples of Carolino rice presented total starch percentages between 64.52 (for Cb) to 71.52% (for Cw) with low amylose content (16.19-19.95%, varying in the following order Cb \ Cab & Cw). During digestion, between 39.43 (for CAb) to 44.48% (for Cb) of starch was hydrolyzed, classifying samples as medium GI foods (61.73-69.17). Starch hydrolysis was accompanied by a decrease of starch granules dimensions. For all samples, area decrease was higher than 59%, perimeter decrease was higher than 37%, feret diameter decrease was higher than 39% and minimum feret diameter decrease was higher than 32%. This work provides new insights to describe, both qualitatively and quantitatively, the fate of rice during digestion, and allowed establishing a comparative basis for the development of rice-based recipes with a lower GI.
Effect of processing paddy on digestibility of rice starch by in vitro studies
Journal of Food Science and Technology, 2010
Paddy (Oryza sativa L) (variety 'IR-64'), was parboiled, puffed by sand roasting and fl aked by edge runner and roller fl aker and variations in physical and physicochemical properties were studied. Moisture contents were lower (5.8-10.8%) in processed rice products compared to raw materials (11.8%). Ratio of rice to sand in the case of puffed rice preparation was optimized. The equilibrium moisture content was 27.4% in raw rice while it was much higher (38.9-81.0%) in processed rice. Sedimentation volume was lowest (6.2 ml) in raw rice and highest (18.8 ml) in popped rice. Starch content was 84.8 and 76.5-83% in raw and processed rice, respectively. In vitro starch digestibility was highest in roller fl aker fl akes and lowest in raw milled rice. Among the ready to eat products, popped rice showed least starch digestibility (~30%).
Changes in the properties of rice varieties with different amylose content on dry heat parboiling
Journal of Cereal Science, 2015
Dry heat parboiling is a unique paddy processing technique that has been scarcely exploited. Dry heat parboiling at high temperature for short time and low temperature for long time on physical and physicochemical properties of three rice varieties differing in amylose content were studied. Hardness of the kernels increased from 66.4 N, 68.8 N and 59.8 N in raw samples to 89.1 N, 86.9 N and 59.8 N in parboiled high amylose, low amylose and waxy rice samples respectively. Rapid migration and evaporation of water from severely heated kernels caused cavity formation at the centre. Irreversible damage of amylopectin structures to leachable fractions caused continuous rise of the pasting curve. Crystallinity was thereby reduced. Parboiled high amylose samples gave X-ray diffraction patterns with peaks characteristic of A, B and Vtype starch crystallinity. Crystalline starch-lipid complexes were observed in low amylose and waxy rices. The significant increase in the amount of rapidly digestible starch from 56.7%, 61.7% and 66.6% in raw samples to 92.1%, 90.8% and 94.8% respectively in severely processed rice samples and subsequent reduction in resistant starch from 24.5%, 21.2% and 18.4% to 0.4%, 1.9% and 0.1% indicated possibilities for targeted food use of the dry heat parboiled samples.