Development of food products based on millets, legumes and fenugreek seeds and their suitability in the diabetic diet

Critical Review on Nutritional, Bioactive, and Medicinal Potential of Spices and Herbs and Their Application in Food Fortification and Nanotechnology

Medicinal or herbal spices are grown in tropical moist evergreen forestland, surrounding most of the tropical and subtropical regions of Eastern Himalayas in India (Sikkim, Darjeeling regions), Bhutan, Nepal, Pakistan, Iran, Afghanistan, a few Central Asian countries, Middle East, USA, Europe, South East Asia, Japan, Malaysia, and Indonesia. According to the cultivation region surrounded, economic value, and vogue, these spices can be classified into major, minor, and colored tropical spices. In total, 24 tropical spices and herbs (cardamom, black jeera, fennel, poppy, coriander, fenugreek, bay leaves, clove, chili, cassia bark, black pepper, nutmeg, black mustard, turmeric, saffron, star anise, onion, dill, asafoetida, celery, allspice, kokum, greater galangal, and sweet flag) are described in this review. These spices show many pharmacological activities like anti-inflammatory, antimicrobial, anti-diabetic, anti-obesity, cardiovascular, gastrointestinal, central nervous system, and antioxidant activities. Numerous bioactive compounds are present in these selected spices, such as 1,8-cineole, monoterpene hydrocarbons, γ-terpinene, cuminaldehyde, trans-anethole, fenchone, estragole, benzylisoquinoline alkaloids, eugenol, cinnamaldehyde, piperine, linalool, malabaricone C, safrole, myristicin, elemicin, sinigrin, curcumin, bidemethoxycurcumin, dimethoxycurcumin, crocin, picrocrocin, quercetin, quercetin 4'-O-β-glucoside, apiol, carvone, limonene, α-phellandrene, galactomannan, rosmarinic acid, limonene, capsaicinoids, eugenol, garcinol, and α-asarone. Other than that, various spices are used to synthesize different types of metal-based and polymer-based nanoparticles like zinc oxide, gold, silver, selenium, silica, and chitosan nanoparticles which provide beneficial health effects such as antioxidant, anti-carcinogenic, anti-diabetic, enzyme retardation effect, and antimicrobial activity. The nanoparticles can also be used in environmental pollution management like dye decolorization and in chemical industries to enhance the rate of reaction by the use of catalytic activity of the nanoparticles. The nutritional value, phytochemical properties, health advantages, and both traditional and modern applications of these spices, along with their functions in food fortification, have been thoroughly discussed in this review.

A Systematic Review and Meta-Analysis of the Potential of Millets for Managing and Reducing the Risk of Developing Diabetes Mellitus

Millets (including sorghum) are known to be highly nutritious besides having a low carbon footprint and the ability to survive in high temperatures with minimal water. Millets are widely recognised as having a low Glycaemic Index (GI) helping to manage diabetes. This systematic review and meta-analyzes across the different types of millets and different forms of processing/cooking collated all evidences. Of the 65 studies that were collected globally, 39 studies with 111 observations were used to analyze GI outcomes and 56 studies were used to analyze fasting, post-prandial glucose level, insulin index and HbA1c outcomes in a meta-analysis. It is evident from the descriptive statistics that the mean GI of millets is 52.7 ± 10.3, which is about 36% lower than in typical staples of milled rice (71.7 ± 14.4) and refined wheat (74.2 ± 14.9). The descriptive, meta and regression analyses revealed that Job's tears, fonio, foxtail, barnyard, and teff were the millets with low mean GI (<55) that are more effective (35–79%) in reducing dietary GI than the control samples. Millets with intermediate GI (55–69) are pearl millet, finger millet, kodo millet, little millet, and sorghum which have a 13–35% lower GI than the control with high GI (>69). A meta-analysis also showed that all millets had significantly (p < 0.01) lower GI than white rice, refined wheat, standard glucose or white wheat bread except little millet which had inconsistent data. Long term millet consumption lowered fasting and post-prandial blood glucose levels significantly (p < 0.01) by 12 and 15%, respectively, in diabetic subjects. There was a significant reduction in HbA1c level (from 6.65 ± 0.4 to 5.67 ± 0.4%) among pre-diabetic individuals (p < 0.01) who consumed millets for a long period. Minimally processed millets were 30% more effective in lowering GI of a meal compared to milled rice and refined wheat. In conclusion, millets can be beneficial in managing and reducing the risk of developing diabetes and could therefore be used to design appropriate meals for diabetic and pre-diabetic subjects as well as for non-diabetic people for a preventive approach.

Physical properties, sensory acceptance, postprandial glycemic response, and satiety of cereal based foods enriched with legume flours: a review

Legumes are rich in proteins and widely consumed around the world. Their consumption has been associated with improved glycemic and lipidemic profile and positive alterations of gut microbiota. These beneficial effects have created a growing scientific interest in the role of legume-enriched foods on the promotion of human health. The aim of this review was to critically record the studies examining the nutritional value and textural properties of these products, as well as their efficacy on lowering postprandial glucose response and satiety. Reviewed data have shown that cereal products with high nutritional value are formulated when fortified with legume flours. The postprandial glucose response appears to be ameliorated and the enriched foods have a medium or a low glycemic index, however not enough data are presented referring to the appetite hormones responses. Textural properties are affected by the addition of legumes and occasionally, when substitution level is high, the final product has not acceptable odor and appearance. To overcome this barrier, particular food processes such as fermentation, extrusion and addition of hydrocolloids, are used and have shown great results on the textural and sensory properties of the final products. The development of healthy legume-enriched cereal-based products is of great importance for the increase of legume consumption and the promotion of public health.

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 Sensory Evaluation of Whole Grain Based Multigrain Indian Breads (Rotis)

Whole grain-based foods have been shown to reduce the risk of development of metabolic syndrome. In this study, we formulated whole grain-based multigrain flour and analyzed for available carbohydrate content, glycemic index (GI), and sensory evaluation. The multigrain flour composition 1 (C1) and composition 2 (C2) were formulated using defatted soya or bengal gram as a source of protein along with millets (40∼45%) and whole cereals. The proximate composition was calculated using Indian food composition tables. The microbial load and free fatty acid contents were analyzed in flour samples that were stored for different durations. The total dietary fiber, protein, and carbohydrate contents per 100 g of C1 and C2 flours were in the range of 11∼14, 13∼15, and 60 g, respectively. The available carbohydrate content in C1 and C2 were 55.4 and 62.3 g, and the in vivo GI was 63.2 and 66.2%, respectively. The acceptability scores of C1 and C2 products were in the range of 3.38 to 3.39 on the 5 points Hedonic scale. The multigrain flours were stable for 3 months based on microbial load and rancidity. The observed GIs of the multigrain flour were much lower than that of commercial refined wheat products. Therefore, these products may be recommended to regular diet plans to help prevent and/or ameliorate metabolic syndrome in the general population.

Analysis of spatial distribution of genetic diversity and validation of Indian foxtail millet core collection

Foxtail millet [Setaria italica (L.) P. Beauv.] is an important small millet, grown as a short duration, drought tolerant crop across the world. This crop can be grown on wide ranges of soil conditions and has an immense potential for food and fodder in rainfed and arid regions of the India. In the present study, 31 primer pairs (27 SSR and 4 EST-SSR) were used to analyse the genetic diversity in 223 core collection accessions. Analysis resulted in detection of a total of 136 alleles with an average of 4.38 alleles per locus. Among these 136 alleles, 22 were rare, 70 were common and 44 were frequent. The PIC value ranged from 0.01 to 0.86 with an average of 0.31. The average number of observed alleles ranged from 2.0 (northern hills of India accessions) to 4.06 (exotic) with an average of 2.72. The mean Shannon's Information Index ranged from 0.44 (northern hills of India) to 0.69 (exotic) with an average of 0.52. Pair-wise Fst values indicated little to moderate genetic differentiation among the group of accessions. UPGMA clustering grouped the accessions into two major groups while analysis for population substructure indicated presence of four subpopulations. However there was no statistically well supported grouping of the accessions based on eco-geographic specificities. The core collection designated here represented substantial genetic diversity at molecular level, hence may be a good source of diversity for use in foxtail improvement programs in the region.

Enhancement of attributes of cereals by germination and fermentation: a review

The nutritional quality of cereals and the sensorial properties of their products are sometimes inferior as compared to other sources of food which is due to the lower protein content and starch availability, the presence of determined antinutrients (phytic acid, tannins, and polyphenols) and the coarse nature of the grains. To ameliorate the nutritional qualities of cereals, they are processed in a number of ways. This review summarizes the enhancement in the nutritional value as well as the functional characteristics of cereals due to germination and fermentation treatment. The protein concentration increases and the amino acid profile is balanced by germination and fermentation. The antinutritional factors are reduced increasing the mineral availability from the cereals. Germination enhances the quality of nutrients and bioactive compounds of cereals thereby increasing the content in proteins, amino acids, sugars, and vitamins. The functional properties of cereals is enhanced due to generation of biofunctional substances, increase in protein solubility, in vitro protein digestibility and lowering of glycemic index.

Ma-Pi 2 macrobiotic diet and type 2 diabetes mellitus: pooled analysis of short-term intervention studies

The macrobiotic, Ma-Pi 2 diet (12% protein, 18% fat and 70% carbohydrate), has shown benefit in adults with type 2 diabetes mellitus (T2DM). This pooled analysis aims to confirm results from four, 21-day intervention studies with the Ma-Pi 2 diet, carried out in Cuba, China, Ghana and Italy. Baseline and end of study biochemical, body composition and blood pressure data, were compared using multivariate statistical methods and assessment of the Cohen effect size (d). Results showed that all measured indicators demonstrated significant changes (p < 0.001); most of them with a very high (d ≥ 1.30), or high (d = 0.80-1.29) effect size. The global effect size of the diet was Italy (1.96), China (1.79), Cuba (1.38) and Ghana (0.98). The magnitude of the individual effect on each variable by country, and the global effect by country, was independent of the sample size (p > 0.05). Similarly, glycemia and glycemic profiles in all four studies were independent of the sample size (p = 0.237). The Ma-Pi diet 2 significantly reduced glycemia, serum lipids, uremia and cardiovascular risk in adults with T2DM. These results suggest that the Ma-Pi 2 diet could be a valid alternative treatment for patients with T2DM and point to the need for further clinical studies. Mechanisms related to its benefits as a functional diet are discussed.

Finger millet (Ragi, Eleusine coracana L.): a review of its nutritional properties, processing, and plausible health benefits

Finger millet or ragi is one of the ancient millets in India (2300 BC), and this review focuses on its antiquity, consumption, nutrient composition, processing, and health benefits. Of all the cereals and millets, finger millet has the highest amount of calcium (344mg%) and potassium (408mg%). It has higher dietary fiber, minerals, and sulfur containing amino acids compared to white rice, the current major staple in India. Despite finger millet's rich nutrient profile, recent studies indicate lower consumption of millets in general by urban Indians. Finger millet is processed by milling, malting, fermentation, popping, and decortication. Noodles, vermicilli, pasta, Indian sweet (halwa) mixes, papads, soups, and bakery products from finger millet are also emerging. In vitro and in vivo (animal) studies indicated the blood glucose lowering, cholesterol lowering, antiulcerative, wound healing properties, etc., of finger millet. However, appropriate intervention or randomized clinical trials are lacking on these health effects. Glycemic index (GI) studies on finger millet preparations indicate low to high values, but most of the studies were conducted with outdated methodology. Hence, appropriate GI testing of finger millet preparations and short- and long-term human intervention trials may be helpful to establish evidence-based health benefits.

Nutrigenomics research: a review

The excitement about nutrigenomics comes from a growing awareness of the potential for modifications of food or diet to support health and reduce the risk of diet-related diseases. It is an emerging field that tends to unfold the role of nutrition on gene expression which brings together the science of bioinformatics, nutrition, molecular biology, genomics, epidemiology, and molecular medicine. The present review focuses on nutrigenomics research and to find out India's status with respect to other countries. It covers the general overview of nutrigenomics, its associated diseases, and the role of SNP in gene alteration, diet supplementation and public awareness. It is understood that with the increasing changes in the food habits and life styles, people are becoming more prone to diet related disorders. Therefore there is an urgent need to boost more research in this field to help people in understanding the relationship between diet and health, and to ensure that everyone benefits from the genomic revolution.

Analysis of molecular genetic diversity in a representative collection of foxtail millet [Setaria italica (L.) P. Beauv.] from different agro-ecological regions of India

Foxtail millet [Setaria italica (L.) P. Beauv.], an important crop of East Asia is known for its drought tolerance and was once an indispensible crop of vast rainfed areas in semi-arid regions in India. In India it is cultivated in Andhra Pradesh, Karnataka, Maharashtra, Tamil Nadu, Rajasthan, Madhya Pradesh, Uttar Pradesh and north eastern states. The grain finds use in several local recipes such as roti (bread), jaula, singal, sirol. Foxtail millet grain contains 12.3 % protein, 4.7 % fat, 60.6 % carbohydrates, and 3.2 % ash. The present study was conducted to analyse the genetic diversity among foxtail accessions from different states of India and a few exotic accessions using RAPD and ISSR techniques and identify diverse accessions for use in variety improvement programmes. A set of 125 foxtail millet accessions selected from 11 different agro-ecological regions of India were analyzed using random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) marker techniques. A total of 146 (115 RAPD and 31 ISSR) scoreable markers were generated with 16 RAPD and four ISSR primers. The dendrogram generated using Nei's genetic distances and principal component analyses revealed presence of two clusters and two subclusters in group I. The accessions from Andhra Pradesh, Karnataka, Maharashtra and Uttarakhand were more diverse since they were distributed in both the clusters. There was no clear geographical differentiation observable. The bootstrap support for the major groups identified was strong (above 80 %) indicating good statistical support. The average value of Nei and Li's genetic distance was lowest (0.081) for accessions from West Bengal while the collections from Karnataka showed highest dissimilarity (average genetic distance = 0.239). The average genetic distance for all 125 accessions together was 0.177 indicating presence of only moderate genetic diversity in the collections. The analysis of molecular variance indicated that only 2.76 % variation was explained by variations among the groups and 11.55 % among populations within groups. However the percentage of variation observed within populations was high (85.68). The value of Fst was observed to be very low (0.028) indicating low differentiation of the accessions analysed. The population genetic analysis carried out indicates that highest number of alleles per locus (1.745 ± 0.438) was observed for Andhra Pradesh with 35 accessions. When four eco-geographic regions were considered, the southern region comprising AP, Karnataka and TN showed the highest number of alleles per locus (1.787 ± 0.411). The value of Gst was lowest for south (0.123) and highest for central west (0.455). This indicated that all the landraces from south share common alleles. The gene flow between the accessions from different regions was also observed to be high with the highest migration (3.557) recorded for south.

Fenugreek bread: a treatment for diabetes mellitus

Use of fenugreek, a food with demonstrated efficacy in lowering blood sugar, is limited by its bitter taste and strong flavor. A bread incorporating fenugreek using a proprietary process was tested for its taste acceptability and its effect on carbohydrate metabolism. We developed a fenugreek bread formula that was produced in a commercial bakery by incorporating fenugreek flour into a standard wheat bread formula. Whole wheat bread was prepared by the same formula in the same bakery using wheat flour. Eight diet-controlled diabetic subjects were served two slices (56 g) and 5% fenugreek. Blood glucose and insulin were tested periodically over a 4-hour period after consumption. The tests were run on two occasions 1 week apart, once with the fenugreek bread and once with regular bread. The study was double-blind, and the order was randomized and balanced. Fenugreek and whole wheat bread samples were evaluated for sensory attributes and nutrient composition. There was no statistically significant difference in proximate composition, color, firmness, texture, and flavor intensity between the fenugreek and wheat bread (P > .05). The area under the curve for glucose and insulin was lower in the fenugreek condition, but only reached significance with insulin (P < .05). The fenugreek-containing bread was indistinguishable from the whole wheat bread control. Normally, fenugreek flour impacts bread quality negatively. The bread maintained fenugreek's functional property of reducing insulin resistance. Acceptable baked products can be prepared with added fenugreek, which will reduce insulin resistance and treat type 2 diabetes.

Meal replacement with mixed rice is more effective than white rice in weight control, while improving antioxidant enzyme activity in obese women

The physiologic consequences of using white rice or mixed rice were evaluated in overweight Korean women (body mass index > or = 25 kg/m(2)) over a period of 6 weeks. Forty women between 20 and 35 years of age were randomly divided into 2 groups who consumed 1 of 2 low-energy meal replacements containing either white rice (WR group) or mixture of brown rice and black rice (BRBL group). The subjects were not allowed to have any food other than the low-energy meal replacement 3 times a day and snacks provided by the researcher. The changes in anthropometric indices and blood parameters such as lipid levels and antioxidant activities were measured every 3 weeks during the dietary intervention. The subjects showed a significant reduction in weight, body mass index, and body fat (%) during the experimental period, with the BRBL group exhibiting levels of all 3 parameters significantly lower than those of the WR group (P < .05). The levels of total cholesterol and triacylglycerols decreased gradually and significantly after intervention in both groups, with no significant difference between groups. High-density lipoprotein cholesterol was significantly elevated in the BRBL group but not in the WR group. Superoxide dismutase activity was not affected by dietary intervention, but glutathione peroxidase activity in the BRBL group was higher than in the WR group, and the level of thiobarbituric acid-reactive substance was lower in the BRBL group compared to the WR group. In conclusion, meal replacement with mixed rice was superior to replacement with white rice in weight control, improving antioxidant enzyme activity, and as such, should be recommended for diet therapy in obese women.

Glycaemic and insulin responses of six traditional Sudanese carbohydrate-rich meals in subjects with Type 2 diabetes mellitus

AIMS

The objective of this study was to investigate the influence of six Sudanese traditional carbohydrate-rich meals on glucose and insulin responses and to formulate appropriate dietary guidelines based on glycaemic excursions of traditional foods.

METHODS

On six occasions with 1-week intervals, 10 Type 2 diabetic subjects consumed six Sudanese traditional carbohydrate-rich meals. The following meals were tested and also analysed for their composition: wheat gorasa (pancakes), sorghum kisra (flat bread) and sorghum acida (porridge), millet kisra and millet acida and maize acida. Blood samples were collected before and after meal ingestion at 0, 30, 60, 120 and 240 min and analysed for plasma glucose and plasma insulin and incremental areas under the curves (AUC) were calculated.

RESULTS

A significant variation in AUC for glucose and insulin responses were found between meals, the over all differences in incremental AUCs between the six meals were significant for both plasma glucose (P = 0.0092) and insulin (P = 0.0001). The 2-h glucose values were 10.5 +/- 2.7 for sorghum flatbread, 9.5 +/- 3.1 for sorghum porridge, 10.3 +/- 3.4 for millet flatbread, 10.6 +/- 3.6 for millet porridge, 11.4 +/- 2.7 for maize porridge and 8.7 +/- 2.4 for the wheat pancakes. The comparison between the AUCs of the meals showed that millet acida (porridge) followed by wheat gorasa (pancakes) displayed significantly lower post-prandial glucose and insulin responses, whereas maize acida induced a higher post-prandial glucose and insulin response.

CONCLUSIONS

The comparison of glycaemic and insulin responses to six traditional Sudanese meals show differences of clinical importance, and could form a basis for dietary advice to diabetic subjects in Sudan and countries sharing similar food traditions.

Diabetes mellitus and obesity

Numerous vitamins, herbs, supplements, and other agents are readily available for the treatment of diabetes and obesity. Many of these products have little evidence-based medical support to prove the efficacy of these supplements. The physician must be aware that their patients are using these products and must be knowledgeable about their side effects and drug-herb interactions. Our patients have tremendous access to medical information in the lay literature and on the internet. They are using this information to gain access to various diet therapies. Numerous fad diets consisting of various combinations of protein, carbohydrate, and fat are widely publicized but not grounded in evidence. Liquid diets and supplements are readily available and widely used by the public with little long-term beneficial effects on obese patients. Other alternative methods, such as hypnotherapy, acupuncture, biofeedback, and electrogalvanic therapy, have become widely available and seem to have little adverse reaction, but whose benefits remain to be proved. The physician must recognize the widespread use of these products and work with patients and alternative practitioners to deliver comprehensive quality care. Physicians who become comfortable with these products should consider their judicious use while monitoring for side effects and drug interaction. It is hoped that with further evidence-based study many of these products and techniques will enter mainstream medicine.