ESR spectroscopic study reveals higher free radical quenching potential in kodo millet (Paspalum scrobiculatum) compared to other millets

Six different millets kodo millet (Paspalum scrobiculatum), finger millet (Eleusine coracana), little millet (Panicum miliare), foxtail millet (Setaria italica), barnyard millet (Echinochloa utilis) and great millet (Sorghum bicolor) grown in India and their white varieties were screened for free radical quenching of 1,1, Diphenyl-2-picrylhydrazyl (DPPH) by electron spin resonance (ESR). Methanol extracts of the kodo millet flour showed 70% DPPH quenching in comparison to other millet extracts which showed 15–53%. The white varieties of great millet, finger millet and foxtail millet showed lower quenching than their coloured counterparts, indicating that phenolics in the seed coat could be responsible for the antioxidant activities. However, the content of the phenols and tannin in these grains did not correlate with the antioxidant activities. Kodo millet had the highest DPPH quenching activity followed by great millet and finger millet. Cooking of kodo or finger millet by roasting or boiling reduced the activity. Fractionation of kodo millet in to husk and endosperm also decreased the activity and the phytochemicals appear to act synergistically.     

Bioaccessibility and antioxidant potential of millet grain phenolics as affected by simulated in vitro digestion and microbial fermentation

Dehulled and cooked grains of five millet varieties (kodo, finger, proso, foxtail and pearl) were subjected to in vitro enzymatic digestion and microbial fermentation under physiological conditions in order to determine the bioaccessibility of their phenolic compounds. Extracts recovered as supernatants from enzymatic digestion and microbial fermentation were employed for the determination of their total phenolic content (TPC) and total flavonoid content (TFC), as well as the scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH), peroxyl and hydroxyl radicals. Furthermore, trolox equivalent antioxidant capacity (TEAC), reducing power and ferrous ion chelating activity of the extracts so obtained were evaluated. The DPPH and hydroxyl radical scavenging activities were determined using electron paramagnetic resonance (EPR) spectroscopy. The peroxyl radical activity was measured using an oxygen radical absorbance capacity (ORAC) assay. The TPC ranged from 12.7 to 35.4 and 21.2 to 47.4 μmol ferulic acid equivalents per gram of grain, on a dry weight (dw) basis at the end of intestinal digestion and colonic fermentation, respectively. All five millet varieties exhibited effective antioxidant activity and the order of efficacy differed according to the assay employed. The present study thus demonstrated that phenolic compounds of processed millets were bioaccessible and colonic fermentation released the phenolics bound to the insoluble fibre in the grain.     

The inhibitory effects of ethanol extracts from sorghum,foxtail millet and proso millet on α-glucosidase and α-amylase activities

Cereal crops have recently experienced increased interest due to their potential health benefits. It has been suggested that the intake of whole grain foods is beneficial to the prevention and management of diabetes mellitus. In this study, we investigated the inhibitory effect of 70% EtOH extracts from different cultivars of sorghum, foxtail millet and proso millet on α-glucosidase and α-amylase. Among the six sorghum cultivars, Mongdang-susu(SS-1), Me-susu(SS-2), Susongsaengi-susu(SS-3) and Sikyung-susu(SS-4) extracts exhibited higher inhibitory activities against α-glucosidase (IC₅₀ = 1.1–1.4 μg/ml) than acarbose, reference inhibitor (IC₅₀ = 2.1 μg/ml). In addition, these extracts strongly inhibited degradation of starch by pancreatic and salivary α-amylase, whereas extracts from foxtail and proso millets exhibited no visible or detectible inhibitory effect on α-amylase or on α-glucosidase activity. These in vitro studies indicate the potential of sorghum in the development of effective anti-diabetic agents.     

Preparation and Physicochemical Properties of Starches and Their Fractions from Finger Millet (Eleusine coracana) and Foxtail Millet (Setaria italica)

The isolation and physicochemical properties of starches and their fractions from different varieties of finger millets and foxtail millets have been studied. Starches from all the millets exhibited single stage swelling and low solubility. The Brabender viscosities decreased considerably during cooking. Purna starch had the tendency to retrograde considerably during cooling. Native millet starches were susceptible to glucoamylase attack. Amylose content of the millet starches ranged from 15,5 to 17,5%. Successive leeching of starches with water and alkali yielded different amylose components having different molecular weights and β-amylolysis limit, suggesting the heterogeneity of total amyloses.     

Sweetener Effects on Flaked Millet Breakfast Cereals

White proso and foxtail millets were used in the formulation of a flaked whole grain ready-to-eat (RTE) breakfast cereal where the effects of dried honey or molasses as secondary sweeteners were evaluated. Some sensory attributes were affected by type of millet and by secondary sweetener. Crispness was affected by sweetener type after 4 min hydration. Sweetness scores and color were inversely related, whether evaluated by sensory or instrumental means. The use of 100% millet in RTE breakfast cereals is feasible and the type of sweetener used affects the cereal color, flavor and crispness in milk.     

Physico-chemical Properties of Native and Malted Finger Millet,Pearl Millet and Foxtail Millet Starches

The physico-chemical properties of starches isolated from native and malted finger millet, pearl millet and foxtail millet were studied. Malt starches, as compared with native starches, contained a majority of smaller granules, slightly more amylose, and exhibited higher gelatinisation temperature, lower swelling power, higher solubility in water as well as in dimethyl sulfoxide and lower intrinsic viscosity. The in-vitro digestibility of starches from native and malted millets was more or less similar but it was different for different starches: pearl millet starch was more susceptible whereas finger millet starch was slighly resistant for amylolysis.     

糜子品种理化特性与体外抗氧化性研究

对39个粳性、糯性糜子品种的品质特性进行分析。结果表明,不同糜子品种的红绿值a*、粗脂肪、灰分、直链淀粉、溶解度、膨胀度、DPPH·清除率和糊化特性差异较大。糜子的平均淀粉含量73.91%,蛋白11.37%,粗脂肪4.02%,灰分0.55%,直链淀粉11.81%,支链淀粉62.10%;糜子的多酚、黄酮含量分别为8.20 mg/g、59.00 mg/100 g,对DPPH·和ABTS+·有一定的清除作用。糯性糜子较粳性糜子色泽鲜黄,具有较高的吸水性、溶解度和膨胀度。除破损值外,粳性糜子的各糊化指标值高于糯性糜子。聚类分析将糜子品种分为4类,可满足不同的加工需求。     

Structural and Physical Properties of Starches Isolated from Six Varieties of Millet Grown in China

This study investigated the structural and physical properties of starches extracted from six varieties of millet mainly grown in China. The amylose content of millet starches ranged from 17.6 to 28.4 g/100 g (dry weight basis, db), and a variety of waxy proso millet starch (0.38 g/100 g, db) was identified. These starches exhibited a majority of large polygonal granules with several indentations, few small spherical granules, and A-type crystallinity. Proso millet starch showed prominent paste clarity and freeze-thaw stability, whereas finger millet starch exhibited the highest solubility. Moreover, barnyard millet starch had the lowest sediment volume. The gelatinization enthalpy of proso millet starch was the highest (5.16 J/g). For non-waxy millet starch, the ratio of retrogradation (R%) was positively correlated with amylose content. Among all starches, the storage modulus (G′) was higher than the loss modulus (G″) during heating and cooling. The G′ and G″ of proso millet starch and barnyard millet starch pastes were significantly lower than other starches during cooling. The pasting properties of six millet starches significantly differed, had positive correlation with amylose content, and were affected by NaCl, sucrose, and pH values.     

Natural plant enzyme inhibitors. Protease inhibitors in millets

Protease inhibitory activities were screened in 12 varieties of pearl millet (Pennisetum typhoideum), 12 varieties of echinocloa (Echinocloa colona), 12 varieties of setaria (Setaria italica), 11 varieties of kodo (Paspalum scorbiculatum), 13 varieties of proso (Panicium miliaceum), 11 varieties of miliare (Panicium miliare), 29 varieties of sorghum (Sorghum bicolor) and four varieties of ragi (Eleusine coracana). Proso, miliare and kodo had no detectable inhibitory activity. Pearl millet, setaria and echinocloa millets displayed only antitryptic activity. Ragi had both antitryptic and antichymotryptic activity. Two varieties of sorghum had neither antitryptic nor antichymotryptic activity. In most other strains of sorghum, the antichymotryptic activity was more than the antitryptic activity. Pearl millet, setaria, sorghum and echinocloa extracts inhibited the proteolytic activity of both human and bovine pancreatic preparations.     

Evaluation of functional,antinutritional, pasting and microstructural properties of Millet flours

In the present study finger and pearl millet grains were milled and sieved to obtain flour. The flours were evaluated for chemical composition, nutritional, antinutritional, pasting and micro structural properties. Significant difference (p < 0.05) in nutrient and antinutrient contents was found among the millet flours. Protein, ash and fiber content of millet flours vary from 7.3 to 8.0 g/100 g, 2.73 to 5.16 g/100 g and 3.03 to 3.05 g/100 g. Results obtained for antinutrient factors in finger and pearl millet flours were (3.5 mg/g) and (2.2 mg/g) for tannic acid and (6.1 mg/g) and (9.2 mg/g) for phytic acid respectively. Mineral availability of pearl and finger millet flour (mg/100 g) was (109.2–139.2), (0.73–4.2), (1.18–8.7.0), (15.03–17.36) and (67.53–30.03) for calcium, zinc, iron, sodium and potassium respectively. Finger millet flour showed higher peak viscosity, breakdown, final and set back value compared to pearl millet flour. Findings from the scanning electron microscopy analysis showed microstructural differences in both millet flours. FTIR analysis showed that both finger and pearl millet flours possessed O–H and C–H compounds.     

Effect of processing on the antioxidant activity of millet grains

Millets are generally dehulled and subjected to a hydrothermal treatment before consumption, thus the hulls can be used as a potential source of antioxidants. Several millet grains, namely kodo, finger (Ravi), finger (local), proso, foxtail, little and pearl millet were studied. Antioxidant activities of phenolic extracts obtained from whole grains, as well as their corresponding dehulled and cooked grains and hulls were studied for their total phenolic content (TPC), radical scavenging capacity, and antioxidant activity in a β-carotene/linoleate emulsion. The phenolics present in whole grains were identified and quantified using HPLC and HPLC/MS and results were expressed as total for each of the phenolic groups. The TPC ranged from 2 to 112 μmol ferulic acid equivalents/g defatted meal. All varieties exhibited effective inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, peroxyl and superoxide radicals. Dehulling and cooking affected the TPC and radical scavenging and antioxidant activities of the grains, depending on the variety. In general, the antioxidant activity of phenolic extracts was in the order of hull > whole grain > dehulled grain > cooked dehulled grain With the exception of the two finger millet varieties, hulls of other millet grains had high TPC, thus demonstrating their superior antioxidant activity. Hydroxybenzoic acids, hydroxycinnamic acids and flavonoids in whole grains were identified as contributors to the observed effects. Therefore, dehulling of grain and hydrothermal treatments affect the phenolic content and antioxidant potential of millet grains.     

Changes During Accelerated Storage in Millet–Wheat Composite Flours for Bread

Two millet–wheat composite flours, CF1 and CF2, were formulated based on the rheological and textural properties of dough using response surface methodology. The optimized contents of composite flour CF1 were 61.8% barnyard millet flour, 31.4% wheat flour, and 6.8% gluten, respectively. The optimized components of the composite flour CF2 were barnyard millet flour 9.1%, finger millet flour 10.1%, proso millet flour 10.2%, and wheat flour 70.6%. Millet–wheat composite flours were stored in three different packaging materials, namely, low-density polyethylene (LDPE), high-density polyethylene (HDPE), and metallized polyester (MP), at 90% RH and 40 °C temperature for 90 days. For the packaging of millet–wheat composite flour CF1, MP was found best among the tested packaging materials, where moisture gain in samples was minimum (55%) as compared with materials LDPE (124%) and HDPE (100%). Vitamin loss among the different packaging materials was not significantly different at the 5% level of significance. The shelf lives of the composite flours were estimated based on their critical moisture contents. After 90 days of storage of CF1, the highest retention of starch (91.85%) was recorded in MP packaging followed by HDPE (87.5%) and LDPE (84.8%). However, in CF2, the retention was not significant in all three packaging materials (P?相似文献   

Effect of processing on nutraceutical properties of foxtail millet (<Emphasis Type="Italic">Setaria italica</Emphasis>) varieties grown in India

Six foxtail varieties grown in India were studied for their nutraceutical properties such as phenolics, tannins and antioxidant activity in whole, dehulled (10 and 17 %) and hulls (10 and 17 %) of the grain. Total antioxidant activity was estimated by three different assays viz., Ferric reducing antioxidant power (FRAP), 1,1-diphenyl-2-picryl-hydrazil radical scavenging activity (DRSA), and thiobarbituric acid reactive substances (TBARS). Among the six varieties, SiA-2593 had highest mean total phenolics (TP) (143.56 ± 55 μg PE/g), tannins (413.80 ± 58 mg/100 g), FRAP (1477.83 ± 26 μmol/g), DRSA (81.53 ± 6.9 %) and lowest TBARS (688.04 ± 39 %) followed by SiA-2644. Dehulling of the grain reduced TP by 24.64 and 43.11 %, tannins by 16.13 and 29.61 %, FRAP by 12.09 and 18.81 %, DRSA by 4.07 and 14.76 % and increase of TBARS by 45.29 and 58.21 % at 10 and 17 % dehulling. The hulls obtained after dehulling had higher percentage of TP, tannins, antioxidant activity (higher FRAP and DRSA and lower TBARS value), a positive correlation was observed between FRAP and Tannin (r = 0.90, P < 0.01) and TP (r = 0.86, P < 0.01) values and a negative correlation with TBARS (r = 0.85, P < 0.01). The results of the present study are useful in selecting the foxtail millet variety and processing conditions for development of functional and nutraceutical foods for various health benefits, however the functional properties of these varieties need to be studied.     

基于主成分分析的21种粳性黄米品质评价

目的:对不同粳性黄米品种的品质进行评价。方法:以21个粳性黄米品种为试验材料,测定其营养成分、糊化特性、蒸煮特性及质构特性,分析品质差异及指标相关性,运用主成分分析进行综合评价。结果:质构特性、粗脂肪含量、回生值、破损值、最终黏度在品种间差异较大,起糊温度和淀粉含量的变异系数较小,是较为稳定的指标。主成分分析结果显示前3个主成分反映了原变量72.04%的信息,筛选出最终黏度、回生值、硬度和黏附性为关键指标,根据综合得分评价出粳性黄米品种的综合品质优劣。结论:陇糜10号、内糜9号、陇糜8号、榆糜3号、宁糜13号的综合品质最优,最终黏度、回生值、硬度和黏附性可作为粳性黄米品质的代表性指标,用于指导黄米品种筛选。     

Geographical origin traceability of foxtail millet based on the combination of multi-element and chemical composition analysis

The potential approach of classifying foxtail millet according to geographical origin was investigated using mineral element and chemical composition analysis of samples from various provinces in China. Total 16 mineral elements and five chemical compositions of foxtail millets were analyzed. There were significant differences in 12 elements of millets from different regions. Notable differences were also observed for chemical composition, with Hebei samples showing higher protein content, Henan samples showing higher fat and ash contents and Shandong samples showed higher dietary fiber and amylose contents. Based on the combination of both methods, discriminant analysis provided optimal discrimination among the various geographical origins with a 95.2% classification rate. Our study provides an effective tool to trace the foxtail millet geographic origin through a combination of multi-element and chemical composition analysis.     

全国主要谷子品种的营养及食用品质分析

为全面了解我国主推谷子品种的营养及食用品质情况,从全国11个谷子主产省份收集了2020年收获的103份纯品种谷子样品,对其营养成分和食用品质进行分析。谷子样品粗蛋白、粗脂肪、总淀粉和总膳食纤维平均含量分别为10.4、3.3、69.9、3.22 g/100 g;维生素B₁、B₂平均含量为0.237、0.080 mg/100 g;小米粥的食品评分值平均分为86分。不同省份比较来看,山西省谷子样品各种营养成分平均含量均在全国平均值以上;内蒙古、山东、河南、陕西、辽宁和新疆6省区谷子样品小米粥的食品评分值平均值最高。品种更多的影响谷子的食用品质,省份更多的影响其营养成分,特别是矿物元素的含量。品种和省份的交互作用对粗蛋白、粗脂肪、可溶性膳食纤维和Na含量及粥的适口性的影响均达到显著水平。     

Characterization of proso millet starches from different geographical origins of China

The influence of geographical origin (Lvliang, Baotou, Gulang, and Jilin) on the physicochemical properties of proso millet (Panicum miliaceum L.) starches from China, and starch chemical compositions were studied. Scanning electron microscopy showed that starch granules from millet starches were polygonal and spherical with smooth surfaces with sizes ranging from 2.5 to 12 μm. X-ray diffraction showed that millet starches were typical of A-type starch granules with a mean crystallinity of 35.81%. The transition temperatures (T _o , T _p , and T _c ) and enthalpy of gelatinization (ΔH) of Lvliang, Baotou, Gulang, and Jilin proso millet starches were 66.81 to 70.01°C, 72.79 to 76.55°C, 78.30 to 82.44°C, and 10.4 to 14.46 J/g, respectively. Significant differences (p<0.05) were observed for the amylose content, granule size, peak temperature, gelatinization enthalpy, and peak viscosity temperature among the millet starches. Millet starches may have potential applications in production of puffed starch food products and other food items.     

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Grain samples of nine varieties of pearl millet (P. typhoides) and six varieties of ragi (E. coracona) were analysed before and after malting for total ash, phosphorus, phytin phosphorus, calcium, magnesium, iron, zinc, manganese, copper and chromium contents. Pearl millet alone varietal differences were significant for iron, manganese and chromium contents. Significant nutrient losses in malting were, in pearl millet: iron and manganese, 40%; copper, 30%, and phosphorus, 25% and, in ragi: calcium, 40%; zinc, 30% and copper 25%. As judged by an in vitro method, the availability of iron and zinc in millets improved several fold on malting. The values for ionizable iron (mg per 100 g of raw and malted grains) were 0·64 and 2·70 in pearl millet and 0·29 and 2·98 in ragi. Soluble zinc contents per 100 g of raw and malted grains, respectively were 2·04 and 5·25 mg in pearl millet and 2·15 and 3·24 mg in ragi. Reduction in phytin phosphorus on malting of these millets partly explained the improved availability of iron and zinc.     

Impact of brown foxtail millet (Setaria italica) flour on thermo-mechanical properties of flours from different rice varieties

The physical, functional and thermo-mechanical properties of rice flours prepared from long, round and medium rice grain and of foxtail millet (Setaria italica) flour were investigated. The impact of foxtail millet flour addition on the thermo-mechanical properties to the rice flours was also explored. Rice flour from long grain had higher amylose content (26.37%), while the rice flour from round grain had better hydration properties compared to the other rice flours. The dough from long grain rice flour exhibited higher starch gelatinisation temperature and cooking stability and lower starch retrogradation compared to the other investigated rice flours. Foxtail millet flour addition to the rice flours exerted a lower impact on the thermo-mechanical properties of the dough based on rice flour from long grain compared to the other investigated rice flours. These differences might be due to the differences in terms of starch properties and proximate composition of the flour samples.     

Effect of drying lactic fermented uji (an East African sour porridge) on some carboxylic acids

Maize, finger millet, cassava, maize–finger millet and cassava–finger millet flours were fermented and sun‐, cabinet‐, or drum‐dried. Total titratable acidity (TTA), fixed acidity (FA), pH and carboxylic acids were determined. The TTA of the non‐fermented flours ranged from 0.22%(w/w) lactic acid in cassava to 0.36%(w/w) lactic acid in the maize–finger millet composite. After fermentation the TTA ranged from 3.26%(w/w) lactic acid in cassava–finger millet to 4.54% in maize‐finger millet while FA ranged from 2.86% in cassava–finger millet to 4.26% in cassava and maize–finger millet. Fermentation decreased the pH from about 5.5 to 3.7–4.1. Drying did not change the pH but TTA decreased by 20–60%. Acetic acid levels in the fermented slurries varied from 0.80 to 0.95 µg per 5 µg while those of hexanoic acid varied from 0.9 to 1.8 µg per 5 µg. Propionic acid was absent in the fermented slurries. Acetic and formic acids were completely lost when the fermented slurries were dried. On average hexanoic acid losses on drying varied from 33% in maize to 91% in cassava fermented slurries. These losses were not significantly influenced by the drying system. In sensory evaluation panellists could not detect flavour loss as a result of drying. © 2000 Society of Chemical Industry