Effects of variable steaming on chemical composition, starch characteristics, and glycemic index of basmati (Pusa Basmati 1121) rice

Abstract

Effects of variable steaming on important quality characteristics of Pusa Basamti 1121 rice were evaluated in the study. Pre‐soaked (at 65°C for 345 min) paddy was steamed at variable steaming consisted of 4 pressure levels (0–1.5 kg/cm2) and 5 steaming times (5–25 min). Steaming affected rice quality characteristics significantly (α = 0.05). It increased head rice yield by 12%. Starch, amylose, Am/Ap ratio, crude protein, crude fats, crude fibers, and ash contents of steamed rice varied from 63.34 to 68.24%, 22.83 to 24.40%, 0.53 to 0.58, 8.11 to 8.39%, 2.47 to 2.58%, 1.59 to 1.63%, and 0.75 to 0.77%, respectively. Peak, final, breakdown, and setback viscosities of raw rice were 1,305, 3,995, −4, and 2,693 cP, respectively; however, their values reduced to 114, 216, −1 and 102 cP, respectively, after steaming. Starch crystallinity of raw rice was 28.49% which reduced to 5.72% after steaming. Scanning electron microscopic images indicated that complete gelatinization of starch was observed after steaming at 1.5 kg/cm2 for ≥10 min. Glycemic index of raw PB1121 rice was 58.41 whereas that of rice steamed at 1.5 kg/cm2 for 20 min was 47.04. Based on results, steaming at 1.5 kg/cm2 for 20 min was found more appropriate to achieve higher HRY (54.16%) and to reduce GI considerably (47). Practical applications Effects of variable steaming on chemical composition, starch characteristics and GI of PB1121 rice were evaluated in present study. Study demonstrated that steaming step alone brings considerable alterations in the overall quality of PB1121 rice. In present times, millers and traders strongly look for rice with higher milling yield, lower pasting viscosities (indicator of better cooking quality) and low GI. Therefore, results of present study would be useful to the millers to produce rice with higher HRY, improved cooking quality and lower GI. Severity of steaming parameters (i.e., steaming pressure and steaming time), during parboiling, would be decided if one knows the qualitative changes occurring in the parboiled grains.

Textural Properties, Resistant Starch, and in Vitro Starch Digestibility as Affected by Parboiling of Brown Glutinous Rice in a Retort Pouch

“…The brown glutinous rice which was soaked at 90 0 C and steamed until 100% gelatinization has the lowest GI value (61.32 or 7.72% reduction). This is a similar value when compared to the previous study of Kale et al, 17 , which investigated the effect of parboiling on GI of Basmati rice, the result showed that there is 6-8% GI value reduction. During cooking, the heat, the amount of water, and the cooking time affected the GI of food.…”

“…Normally, rice with higher levels of RS has a lower GI value. 16 The effects of parboiling techniques on GI have been investigated by Kale et al, 17 The results showed that parboiling at temperatures higher than 60 0 C could decrease the GI from 58 to 54. This was due to amylose-lipid complexes being formed and digested more slowly in the small intestine.…”

Evaluation of indigenous aromatic rice cultivars from sub-Himalayan Terai region of India for nutritional attributes and blast resistance

“…Many of the previous work has also reported strong negative correlation of RS and GI in rice cultivars even after cooking 44 where as high amylose content rice cultivars have been reported to have low GI 24 , 45 . GI of Pusa Basmati 1121 has been reported as 58.41% which has been shown to reduce by steaming of the paddy or by different cooking treatments 46 , 47 . As compared to basmati; the land races like, ‘Kataribhog’, ‘A-1-1’, ‘Dubarikomal’, ‘KNS-2B-S1’, ‘TPUR-B-1 (IET 28104)’ etc.…”

Effect of soaking medium on the physicochemical properties of parboiled glutinous rice of selected Laotian cultivars

“…Moreover, parboiling may result in increased resistant starch fraction and low glycemic index (GI) which are health-promoting. [19] Traditionally to make parboiled rice, paddy is soaked in water for 48 h followed by steaming and drying. [3] As the global food index is taking a step forward from food security to food safety, innovations and improvements in the parboiling process are becoming a subject of research interest.…”