Carbohydrate profiling & glycaemic indices of selected traditional Indian foods.

Background & objectives: Consumption of high glycaemic index (GI) food is associated with a high risk for diabetes. There is a felt need to understand the GI of common Indian traditional foods using standard GI protocols. The present study was aimed to analyse the carbohydrate profile of common traditional Indian food preparation and to determine their GI using standardized protocols. Methods: Twelve food preparations made of millets, wheat, maize and pulses were evaluated for nutrient composition including detailed carbohydrate profiling and tested for GI in healthy volunteers using standard methodology. Capillary blood glucose responses for the test foods containing 50 g available carbohydrates were recorded and compared to the reference food (50 g glucose). GI was calculated from the incremental area under the curve (IUAC) for the test and reference foods. Results: Available carbohydrate content of the food preparations ranged between 13.6 and 49.4 g per cent. Maize roti showed the highest total dietary fibre (7.5 g%). White chick pea 'sundal' showed highest resistant starch content (3.95 g%). Amongst the 12 test foods, five fell in the high GI category (finger millet balls, sorghum, pearl millet and maize roti), four in the medium GI category (sorghum idli, wheat dosa, methi roti and adai) and three in the low GI category (broken wheat upma, white peas sundal and white chick peas sundal). Interpretation & conclusions: Merely being a whole grain-based food does not qualify for a lower GI. The method of processing, food structural integrity and preparation could influence the GI. The type and quality of fibre are important than the quantity of fibre alone. Judicious planning of accompaniments using low GI legumes may favourably modify the glycaemic response to high GI foods in a meal.

The Role of Oat Nutrients in the Immune System: A Narrative Review.

Optimal nutrition is the foundation for the development and maintenance of a healthy immune system. An optimal supply of nutrients is required for biosynthesis of immune factors and immune cell proliferation. Nutrient deficiency/inadequacy and hidden hunger, which manifests as depleted nutrients reserves, increase the risk of infectious diseases and aggravate disease severity. Therefore, an adequate and balanced diet containing an abundant diversity of foods, nutrients, and non-nutrient chemicals is paramount for an optimal immune defense against infectious diseases, including cold/flu and non-communicable diseases. Some nutrients and foods play a larger role than others in the support of the immune system. Oats are a nutritious whole grain and contain several immunomodulating nutrients. In this narrative review, we discuss the contribution of oat nutrients, including dietary fiber (ß-glucans), copper, iron, selenium, and zinc, polyphenolics (ferulic acid and avenanthramides), and proteins (glutamine) in optimizing the innate and adaptive immune system's response to infections directly by modulating the innate and adaptive immunity and indirectly by eliciting changes in the gut microbiota and related metabolites.

Assessment of quality of minor millets available in the south Indian market & glycaemic index of cooked unpolished little & foxtail millet.

BACKGROUND & OBJECTIVES: : Millets are widely marketed as healthier alternatives to white rice (WR). This study was conducted with two aims: firstly, to look at the nature and quality of minor millets available in the Chennai market and secondly, to estimate the glycaemic index (GI) of unpolished forms of the two most widely available minor millets, i.e. little (LM) and foxtail millet (FXM). METHODS: : A market survey was conducted of 100 food stores in four zones of Chennai, south India. Morphological features of market millet samples were compared with that of unpolished millets under stereo-zoom microscope, and the claims declared on the pack were evaluated. A consumer perception survey was conducted among 20 minor millet-consuming female homemakers. Finally, the GI of unpolished LM and FXM was evaluated using a validated protocol in 12 healthy volunteers. RESULTS: : Forty eight brands of minor millets were available, with LM and FXM being the most common. Most of the millet samples were identified as highly polished grains using stereo-zoom microscope. The product labels were misleading and showed no scientific backing for claims mentioned on the label. Most participants (12 of 20) were unaware of the fact that millets can also be polished like rice. Both LM and FXM exhibited high GI (88.6±5.7 and 88.6±8.7, respectively). INTERPRETATION & CONCLUSIONS: The availability and knowledge regarding unpolished millets was low. Both LM and FXM exhibited high GI. Hence, substituting millets for WR might be of limited benefit considering the glycaemic property in the prevention and management of chronic non-communicable diseases such as T2DM.

Glycemic Index and Microstructure Evaluation of Four Cereal Grain Foods.

To determine the glycemic index (GI) of selected cereals and association with their microstructure. The GI of whole grain pilaf (WGP), instant brown rice (IBR), whole maize ugali (MWU), and refined maize ugali (RMU) was assessed in a randomized trial. Fourteen healthy participants with mean age of 25 years were administered 50 g portions of available carbohydrates from glucose and various test foods after an overnight fast on separate occasions. Capillary blood samples of participants were used to measure blood glucose over 2 hr. The GI was calculated as per standard protocol. The microstructure of test foods, determined by scanning electron microscopy was evaluated to understand the measured GI values. The GI (mean ± standard error) of IBR was the highest (87.8 ± 6.8) followed by RMU (74.7 ± 6.5) and WMU (71.4 ± 5.1). WGP had medium GI (58.9 ± 5.1; P < 0.01 vs. IBR). Microstructure examination of IBR revealed disruption of bran layer and presence of fissures indicating loss of intactness of bran. Stereozoom images for WGP revealed intact bran and germ. For RMU and WMU, the grain was milled leading to loss of integrity. IBR, RMU, and WMU have high GI values, which is likely due to disruption of bran layer, endosperm modification (IBR), and loss of grain matrix (WMU, RMU). WGP has medium GI probably due to fairly intact bran and germ. PRACTICAL APPLICATION: Wholegrain or whole meal flour may not necessarily be low in glycemic index (GI; low GI < 55; medium 55 to 69 and high GI ≥70). "Ugali" a commonly consumed cereal staple food in Tanzania made from either refined or whole meal maize flour was found to be a high GI food. Intact whole grain foods, such as whole grain pilaf (mixed intact whole grains) is a healthier alternative to milled whole grains such as whole meal maize flour. Instant quick cooking brown rice exhibited a high GI, due to the processing method, suggesting that regular brown rice may be a healthier option.

Development and evaluation of nutritional, sensory and glycemic properties of finger millet (Eleusine coracana L.) based food products.

BACKGROUND AND OBJECTIVES: Finger millet (Eleusine coracana L.) (FM) is rich in dietary fibre and is therefore expected to elicit a lower glycemic response compared to other grains. However, there is little data on the glycemic properties of FM-based products. We evaluated the nutritional, sensory and glycemic properties of decorticated millet with lower polish (DFM-LDP), flakes (FMF), vermicelli (FMV) and extruded snack (FMES) (both FMV and FMES with 7-8% added soluble fibre). METHODS AND STUDY DESIGN: The nutrient contents of the FM products were evaluated by standard AOAC (Association of Official Analytical Chemists) and AACC (American Association of Cereal Chemists) methods. Sensory evaluation was conducted monadically using a 9-point hedonic scale using untrained panel members. GI testing was conducted using a standardized validated protocol. The study was conducted according to the guidelines laid down by the Declaration of Helsinki, and was approved by the Ethics Committee of the Madras Diabetes Research Foundation. RESULTS: The products had dietary fibre (DF) content between 5.8-15.6 g%. FMES was unique in having a very low fat content (0.17%). Evaluation of sensory perception revealed moderate acceptance of millet based products. The glycemic indices (GI) (mean±SEM) of the products were 84.7±7.7%, 82.3±6.4%, 65.5±5.1% and 65.0±6.6% for DFM-LDP, FMF, FMV and FMES respectively. CONCLUSIONS: DFM-LDP and FMF (purely finger millet based products) elicited higher glycemic responses. Comparatively, FMV and FMES (with added functional ingredients) exhibited medium GI values and, are healthier dietary options. It is possible to prepare FM products with lower GI by utilizing functional ingredients.

Even minimal polishing of an Indian parboiled brown rice variety leads to increased glycemic responses.

BACKGROUND AND OBJECTIVES: To evaluate the effect of polishing on the glycemic properties of Indian parboiled brown rice. METHODS AND STUDY DESIGN: We evaluated the effect of different degrees of polishing on the glycemic and insulinemic responses of Bapatla (BPT-5204), Indian parboiled Indica rice variety. Brown rice (BR), under milled rice (UMR) and white rice (WR) with 2.3% and 9.7% degree of polishing (DOP), respectively, were prepared and evaluated for the glycemic properties. Incremental Area Under the Curves (IAUC) were estimated for both glycemic index (GI) in 12 healthy participants (6 men, 6 women) and 24 hr glycemic response studies in 13 overweight participants (5 men, 8 women) using continuous glucose monitoring (CGM) system with ≈2000 kcal/day rice diets. Differences in pre and post meal insulin (Δ) were assessed. RESULTS: The GI of WR (GI=79.6) and UMR (GI=73) were significantly higher than BR (GI=57.6) (p<0.01). Similar results were obtained for 24 hr glycemic responses [IAUC: WR=58.4, UMR=55.5, BR=34.7 mg*5 min/dL, respectively]. The Δ Insulin responses were lower with BR meals compared with UMR and WR (p=0.025; p=0.003). CONCLUSIONS: Both UMR and WR had a high GI while BR had a medium GI. This could have influenced the 24 h glycaemic and insulinemic responses of BR which had the lowest responses as compared with UMR and WR, and the latter two had similar higher responses. Thus any degree of polishing leads to higher glycaemic responses.

Influence of hydrothermal processing on functional properties and grain morphology of finger millet.

Finger millet was hydrothermally processed followed by decortication. Changes in color, diameter, density, sphericity, thermal and textural characteristics and also some of the functional properties of the millet along with the grain morphology of the kernels after hydrothermal processing and decortication were studied. It was observed that, the millet turned dark after hydrothermal processing and color improved over native millet after decortication. A slight decrease in grain diameter was observed but sphericity of the grains increased on decortication. The soft and fragile endosperm turned into a hard texture and grain hardness increased by about 6 fold. Hydrothermal processing increased solubility and swelling power of the millet at ambient temperature. Pasting profile indicated that, peak viscosity decreased significantly on hydrothermal processing and both hydrothermally processed and decorticated millet exhibited zero breakdown viscosity. Enthalpy was negative for hydrothermally processed millet and positive for decorticated grains. Microscopic studies revealed that the orderly structure of endosperm changed to a coherent mass after hydrothermal processing and the different layers of seed coat get fused with the endosperm.

Health benefits of finger millet (Eleusine coracana L.) polyphenols and dietary fiber: a review.

The growing public awareness of nutrition and health care research substantiates the potential of phytochemicals such as polyphenols and dietary fiber on their health beneficial properties. Hence, there is in need to identify newer sources of neutraceuticals and other natural and nutritional materials with the desirable functional characteristics. Finger millet (Eleusine coracana), one of the minor cereals, is known for several health benefits and some of the health benefits are attributed to its polyphenol and dietary fiber contents. It is an important staple food in India for people of low income groups. Nutritionally, its importance is well recognised because of its high content of calcium (0.38%), dietary fiber (18%) and phenolic compounds (0.3-3%). They are also recognized for their health beneficial effects, such as anti-diabetic, anti-tumerogenic, atherosclerogenic effects, antioxidant and antimicrobial properties. This review deals with the nature of polyphenols and dietary fiber of finger millet and their role with respect to the health benefits associated with millet.

Effect of processing on the microstructure of finger millet by X-ray diffraction and scanning electron microscopy.

Finger millet is one of the important minor cereals, and carbohydrates form its major chemical constituent. Recently, the millet is processed to prepare hydrothermally treated (HM), decorticated (DM), expanded (EM) and popped (PM) products. The present research aims to study the changes in the microstructure of carbohydrates using X-ray diffraction and scanning electron microscopy. Processing the millet brought in significant changes in the carbohydrates. The native millet exhibited A-type pattern of X-ray diffraction with major peaks at 2θ values of 15.3, 17.86 and 23.15°, whereas, all other products showed V-type pattern with single major peak at 2θ values ranging from 19.39 to 19.81°. The corresponding lattice spacing and the number of unit cells in a particular direction of reflection also reduced revealing that crystallinity of starch has been decreased depending upon the processing conditions. Scanning electron microscopic studies also revealed that the orderly pattern of starch granules changed into a coherent mass due to hydrothermal treatment, while high temperature short time treatment rendered a honey-comb like structure to the product. However, the total carbohydrates and non-starch polysaccharide contents almost remained the same in all the products except for DM and EM, but the individual carbohydrate components changed significantly depending on the type of processing.

Amelioration of hyperglycaemia and its associated complications by finger millet ( Eleusine coracana L.) seed coat matter in streptozotocin-induced diabetic rats.

Finger millet (Eleusine coracana) is extensively cultivated and consumed in India and Africa. The millet seed coat is a rich source of dietary fibre and phenolic compounds. The effect of feeding a diet containing 20% finger millet seed coat matter (SCM) was examined in streptozotocin-induced diabetic rats. Diabetic rats maintained on the millet SCM diet (diabetic experimental (DE) group) for 6 weeks exhibited a lesser degree of fasting hyperglycaemia and partial reversal of abnormalities in serum albumin, urea and creatinine compared with the diabetic control (DC) group. The DE group of rats excreted comparatively lesser amounts of glucose, protein, urea and creatinine and was accompanied by improved body weights compared with their corresponding controls. Hypercholesterolaemia and hypertriacylglycerolaemia associated with diabetes were also notably reversed in the DE group. Slit lamp examination of the eye lens revealed an immature subcapsular cataract with mild lenticular opacity in the DE group of rats compared to the mature cataract with significant lenticular opacity and corneal vascularisation in the DC group. Lower activity of lens aldose reductase, serum advanced glycation end products and blood glycosylated Hb levels were observed in the DE group. The millet SCM feeding showed pronounced ameliorating effects on kidney pathology as reflected by near normal glomerular and tubular structures and lower glomerular filtration rate compared with the shrunken glomerulus, tubular vacuolations in the DC group. Thus, the present animal study evidenced the hypoglycaemic, hypocholesterolaemic, nephroprotective and anti-cataractogenic properties of finger millet SCM, suggesting its utility as a functional ingredient in diets for diabetics.

Inhibition of aldose reductase from cataracted eye lenses by finger millet (Eleusine coracana) polyphenols.

Retinopathy is a major cause of blindness in the Western world, while cataract is one of the three major causes of blindness worldwide. Diabetes is one of the major risk factor in retinopathy and cataract. The prevalence of blindness in India is 15 per 1000 while cataract alone accounts for 80% of this blindness. Diabetes induced cataract is characterized by an accumulation of sorbitol which is mediated by the action of a key enzyme aldose reductase (AR). Non-enzymatic glycation (binding of glucose to protein molecule) induced during diabetes appear to be the key factor for AR mediated sugar-induced cataract. Finger millet polyphenols (FMP) being a major anti-diabetic and antioxidant component, we have evaluated them for AR inhibiting activity. Phenolic constituents in FMP such as gallic, protocatechuic, p-hydroxy benzoic, p-coumaric, vanillic, syringic, ferulic, trans-cinnamic acids and the quercetin inhibited cataract eye lens effectively, the latter was more potent with an IC(50) of 14.8nM. Structure function analysis revealed that phenolics with OH group at 4th position was important for aldose reductase inhibitory property. Also the presence of neighboring O-methyl group in phenolics denatured the AR activity. Finger millet seed coat polyphenols (SCP) has been found to inhibit AR reversibly by non-competitive inhibition. Results thus, provide a stronger evidence for the potentials of FMP in inhibiting cataractogenesis in humans.

Glycemic response of rice, wheat and finger millet based diabetic food formulations in normoglycemic subjects.

Food formulations suitable as dietary supplements to diabetic subjects based on wheat, decorticated finger millet, popped (aralu) and expanded (puri) rice each blended separately with legumes, non-fat dry milk, vegetable oils, spices and a few hypoglycemic ingredients were formulated. The formulations contained 13.0-18.3% protein, 11.3-11.8% fat, 59.9-67.5% starch and 13.2-18.0% dietary fiber. A 50-g equivalent carbohydrate portion of the foods in the form of thick porridge was provided to eight healthy adult subjects and the postprandial blood glucose response was determined. The Glycemic Index (GI) values were 55.4+/-9, 93.4+/-7, 105+/-6 and 109+/-8 for wheat-based, millet-based, aralu-based and puri-based formulations. The variations in the GI could be attributed to the nature of available as well as non-available (non-starchy polysaccharides) carbohydrates in the foods besides the processing undergone by the cereal ingredients. The higher GI of rice formulations could be due to the easily digestible nature of starches and also their lower dietary fiber contents. The study revealed the suitability of wheat-based formulation as a food supplement or as meal replacer in diabetic subjects but the unsuitability of rice-based formulations.

Chemical composition of garden cress (Lepidium sativum) seeds and its fractions and use of bran as a functional ingredient.

Garden cress (Lepidium sativum) belonging to the family Cruciferae grown in India, Europe and US is an underutilized crop. The edible whole seed is known to have health promoting properties. Hence, it was assumed that these seeds can be a functional food. A preliminary work on chemical composition of seeds was carried out and the possibility of using it as nutraceutical food ingredient in dietary fiber formulation was explored. Three fractions namely whole meal (WM), endosperm and bran were analyzed for chemical composition. The yield of the endosperm and the bran fraction were 72 and 28%, respectively. The WM, endosperm and bran had 22.5, 27.7 and 12.6% protein, 27.5, 33.1 and 6% fat, 30, 13.6 and 75% dietary fibre (DF), and 1193.00, 945.15 and 1934.57 mg% potassium respectively. The major protein on SDS-PAGE was of 29.5 kDa. The most abundant amino acid was glutamic acid (19.3%) and the essential amino acid, leucine was the highest (8.21 +/- 0.01%) and methionine the lowest (0.97 +/- 0.02%). The major fatty acid was linolenic acid (30.2%) and low amount of erucic acid (3.9%) was also present. Bran having high water holding capacity and high DF, its use as source of DF was explored. The product contained 12% protein, 4% fat and 74.3% DF and exhibited desirable functional properties such as dispersibility, gelling ability, stability, formed homogenous mild alkaline suspension and was comparable to proprietary DF.