Finger millet porridges subjected to different processing conditions showed low glycemic index and variable efficacy on plasma antioxidant capacity of healthy adults

Effect of simulated gastrointestinal digestion on the phenolic composition and biological activities of guava pulp and processing by-products

Powdered samples of guava pulp and processing by-products (single fraction containing crushed seeds, peels, and residual pulp) are rich sources of polyphenols with antidiabetic, anti-obesity, cardioprotective, and anticancer potential. However, post-digestion retention of these bioactivities remains unclear. Therefore, these samples were subjected to in vitro digestion simulating oral, gastric, small intestine, and large intestine phases. Phenolic bioaccessibility was highest upon large intestinal digestion for pulp (62.04 %) and waste (22.49 %), while the lowest occurred in the oral and small intestinal phases. Digestion reduced their antiradical activity and ability to inhibit α-glucosidase (42.42-55.84 %) but enhanced pancreatic lipase inhibition (up to 82.82 %). Digested samples could better suppress oxidative damage to LDL-cholesterol and supercoiled DNA. Phenolic acids and ellagitannins were released after gastric digestion, while proanthocyanidins predominated in intestinal phases. Digestion altered the phenolic composition of samples, positively affecting several bioactivities. Further research should investigate metabolization of polyphenols across intestinal cells to establish bioavailability.

Role of millets in pre-diabetes and diabetes: effect of processing and product formulation

The incidence of pre-diabetes and diabetes has been increasing recently worldwide and considered as a major growing non-communicable disease. Millets are eco-friendly crops which could sustain extensive climatic conditions. The productivity of millets had increased in recent years to meet the nutritional needs of the increasing global population. The factors which affect the starch digestibility pattern in millets are protein, fat, resistant starch, dietary fibre, and anti-nutrients. However, the interplay of these components also affects the starch digestibility pattern in millets during various processing methods such as thermal, non-thermal, chemical, and their combination. The incorporation of native and processed millet in food products varies the in-vitro and in-vivo glycaemic index. The current study further discusses the potential applications of millet in food formulations for pre-diabetic and diabetic population. Hence the appropriately processed millets could be a suggested as a suitable dietary option for pre-diabetic and diabetic population.

Phenolic composition and bioactivities of sea buckthorn (Hippophae rhamnoides L.) fruit and seeds: an unconventional source of natural antioxidants in North America

BACKGROUND

Sea buckthorn (Hippophae rhamnoides L.) was introduced into Canada in the early 2000s. This plant bears fruits with high commercial value in other countries due to its premium oil. Nevertheless, sea buckthorn berries are also a rich source of bioactives with nutraceutical potential, especially the variety grown in Newfoundland (Canada), which has not previously been characterized. As such, this study evaluated the composition of polyphenols in sea buckthorn pomace and seeds, as well as their prospective health-promoting effects.

RESULTS

Polyphenolic identification by high-performance liquid chromatography-ultraviolet-mass spectrometry-time of flight revealed the presence of 24 compounds in the seeds and 16 compounds in the pomace, including phenolic acids, flavonoids, and tannins, with ellagic acid derivative IV (pomace, 52.13 μg g-1) and (+)-catechin (seeds, 690.8 μg g-1) being the most dominant. Sea buckthorn extracts displayed in vitro antidiabetic and anti-obesity potential by inhibiting α-glucosidase (71.52-99.31%) and pancreatic lipase (15.80-35.61%) enzymes, respectively. The extracts also protected low-density-lipoprotein cholesterol (50.97-89.67%) and supercoiled DNA (35.11-79.84%) from oxidative damage.

CONCLUSION

Sea buckthorn berries grown in Canada showed promising health benefits induced by their rich and diverse polyphenolic profile and need to be considered for further commercial expansion as a bioactive-loaded superfruit. © 2024 Society of Chemical Industry.

Nutraceutical Potential of Underutilized Tropical Fruits and Their Byproducts: Phenolic Profile, Antioxidant Capacity, and Biological Activity of Jerivá (Syagrus romanzoffiana) and Butiá (Butia catarinensis)

Jerivá and butiá are under-valued tropical fruits lacking scientific evidence about their nutraceutical potential. Therefore, they were investigated for their phenolic compound composition and biological activities. Free, esterified, and insoluble-bound polyphenols were obtained from powdered jerivá and butiá pomace and seeds. The total phenolic estimation in seeds (jerivá, 36.45 mg GAE/g; butiá, 45.79 mg GAE/g) exceeded pomaces (jerivá, 23.77 mg GAE/g; butiá, 18.69 mg GAE/g). Phenolic extracts demonstrated antidiabetic and antiobesity potential, inhibiting α-glucosidase (30.51-98.43%) and pancreatic lipase (19.66-41.98%). They also suppressed free radical-induced damage to DNA (21.46-92.48%) and LDL-cholesterol (8.27-23.20%). Identified phenolics (51) included multiple phenolic acids, flavonoids, and tannins, predominantly gallic acid derivatives/conjugates. This is the first study to provide a detailed description of the phenolic profile of these fruits and their byproducts coupled with their bioactivities. Butiá and jerivá were demonstrated to be outstanding sources of polyphenols with high nutraceutical potential for bioeconomic exploration.

Anti-diabetic and anti-cancer related health food properties of selected Sri Lankan traditional rice based porridges

Four Sri Lankan porridges including madathawalu (MWP), kaluheenati (KHP), mixed rice of sudu heenati, goda heenati, masuran, and dikwee (MXP) and special traditional porridge (STP) were screened for in vitro glycemic indices (GI), α-amylase inhibition and anti-glycation activities. All four porridges had the medium GI values, those were in the range of 40.5 ± 4 to 63.9 ± 2. The highest antiglycation activity was reported for MWP demonstrating IC50 of 228.20 ± 4.20 µg/mL. In relation to the α-amylase inhibition activity, the porridge extracts of MWP and STP low IC50 values (117.54 ± 1.92 µg/mL and 128.75 ± 5.91 µg/mL) showed their high capability to inhibit α-amylase enzyme. Due to the medium to low GI values and high antiglycation and α-amylase inhibition activities, traditional rice based porridges can be considered as effective for the prevention of diabetic conditions as well as from various complications in diabetic patients. Anticancer activity against human lung and HeLa cell lines revealed that KHP and MXP exhibited anticancer activity (IC50 of 274.6 μg/mL and 940.2 μg/mL respectively) against HeLa- human cervical cancer cells. In conclusion, porridge composites prepared using Sri Lankan traditional rice helped to eliminate or notably reduce nutrient deficiencies, and it provided numerous health benefits and economical gains.

In vitro determination of anti-lipidemic, anti-inflammatory, and anti-oxidant properties and proximate composition of range of millet types and sorghum varieties in Sri Lanka

Methanolic extracts of whole grains of five millet types and two sorghum varieties were evaluated for anti-lipidemic, anti-inflammatory, and a range of anti-oxidant properties in vitro (n = 3 each). Furthermore, proximate composition (n = 3 each) was also studied. Results showed significant differences (P < 0.05) among the selected samples for studied parameters. Pancreatic lipase and cholesterol esterase inhibitory activities of selected samples (2 mg/ml) ranged from 21.16 ± 1.58 to 66.65 ± 3.30 and 17.43 ± 0.60 to 52.09 ± 1.61%, respectively. Nitric oxide inhibitory activity of selected samples (2 mg/ml) ranged from −1.17 ± 0.32 to 13.56 ± 0.93%. Total polyphenolic content (TPC), total flavonoid content (TFC), and total proanthocyanidin content (TPAC) were in the range of 0.19 ± 0.01–12.50 ± 0.87 mg gallic acid equivalents/g, 0.05 ± 0.00–1.57 ± 0.01 mg quercetin equivalents/g, and 0.35 ± 0.01–12.87 ± 0.25 mg cyaniding equivalents/g of samples, respectively. Ferric reducing anti-oxidant power, oxygen radical absorbance capacity, ferrous ion chelating activity, and ABTS and DPPH anti-oxidant properties ranged from 0.15 ± 0.00 to 4.56 ± 0.03 mg of Trolox equivalents (TEs)/g, 0.19 ± 0.01 to 8.50 ± 0.72 mg of TEs/g, 0.13 ± 0.00 to 0.79 ± 0.03 mg EDTA equivalents/g, 0.22 ± 0.00 to 25.57 ± 0.35 mg of TEs/g, and 0.07 ± 0.00 to 22.97 ± 0.83 mg of TEs/g of samples, respectively. Among the studied samples, pigmented sweet sorghum exhibited the highest activities for all the tested parameters. The observed activities were moderate compared to the reference standards used. The highest values for proximate composition parameters tested varied with the different samples studied. In conclusion, the consumption of especially pigmented millet and sorghum in Sri Lanka may play an important role in the prevention and management of oxidative stress–associated chronic diseases. This is the first study to report pancreatic lipase and cholesterol esterase inhibitory activities of any millet types and sorghum varieties in Sri Lanka and the first report of cholesterol esterase inhibitory activity of millet and sorghum the world over.

Effect of processing on the antioxidant activities of porridges and Pittu prepared from finger millets (Eleusine coracana)

Finger millets are important coarse grains that exhibit high levels of phenolic compounds and antioxidant activities among other cereals. Grains are subjected to a number of thermal treatments and this could affect the contents and bioactivities of phenolic compounds. The aim of the present study was to determine the phenolic contents and antioxidant activities of finger millet flour and foods, namely porridges and Pittu subjected to several thermal treatments such as roasting, parboiling, and parboiled roasting of flour and open boiling and steaming of foods prepared using flour. The effect of the addition of spices on phenolic content and antioxidant activities to open boiled foods was determined. Antioxidant activities of phenolic extracts obtained from finger millet flour and foods were studied for their total phenolic, flavonoids and proanthocyanidins contents, radical scavenging capacities, reducing power, ferrous ion chelating capacity, and antioxidant activity in a β-carotene/linoleate emulsion. The roasted flour and foods had higher total phenolic content (TPC) than other counterparts and ranged from 21.58 to 28.63 µmol ferulic acid equivalents/g dry matter. All flour and food preparations exhibited effective inhibition of radicals, reducing power, ferrous ion chelating activity, and antioxidant activity in the β-carotene/linoleate emulsion and the degree of activity depended on the processing conditions adopted in food preparations.

Foods prepared using steaming showed lower phenolic content and antioxidant activities in general than those of open-boiled counterparts. The addition of spices, namely garlic and cinnamon improved the phenolic contents and antioxidant activities of open-boiled porridges. The knowledge generated from this study may help to exploit the use of finger millets as a functional food ingredient to promote health and wellness.

Graphical abstract

The Role of Amaranth, Quinoa, and Millets for the Development of Healthy, Sustainable Food Products-A Concise Review

The selection of sustainable crops adaptable to the rapidly changing environment, which also cater to the dietary needs of the growing population, is a primary challenge in meeting food security. Grains from ancient crops such as amaranth, quinoa, and millets are positioned to address this challenge and hence have gained dietary predominance among cereals and pseudocereals due to their nutritional value and energy efficiency. From a nutritional perspective, they are recognized for their complete protein, phenolic compounds and flavonoids, prebiotic fibers, and essential micronutrients, including minerals and vitamins. Bioactive peptides from their proteins have shown antihypertensive, antidiabetic, antioxidant, and anticancer properties. The nutritional diversity of these grains makes them a preferred choice over traditional cereals for developing healthy, sustainable food products such as plant-based dairy, vegan meats, and gluten-free products. With growing consumer awareness about sustainability and health, the categories mentioned above are transitioning from ‘emerging’ to ‘mainstream’; however, there is still a significant need to include such healthy grains to fulfill the nutritional gap. This review article emphasizes the health benefits of amaranth, quinoa, and millet grains and discusses the recent research progress in understanding their application in new sustainable food categories. The challenges associated with their incorporation into novel foods and future research directions are also provided.

Are Millets More Effective in Managing Hyperlipidaemia and Obesity than Major Cereal Staples? A Systematic Review and Meta-Analysis

Millets are important staples across developing countries in Asia and Africa. A previous systematic review and meta-analysis showed that eating millets significantly controlled hyperlipidaemia and obesity by focusing on a comparison of pre- and post-intervention measurements. This study further provides meta-analysis of the effects of the consumption of millets on hyperlipidaemia and obesity by analysing millets against other staple grains using the difference-in-differences method, where the effects were computed on the Standardised Mean Difference scale. Thus, only studies that included a control group as well as the baseline were included. The results from twelve eligible studies on blood lipid profile show significant (p < 0.05) favourable effects of consuming millets compared to other staples (rice, wheat, and quinoa). Specifically, the effects on total cholesterol, triacylglycerol, and very low-density lipoprotein cholesterol levels were −0.44, −0.29, and −0.41, respectively (p < 0.05), while the effect on the high-density lipoprotein cholesterol level was +0.59 (p < 0.05). In addition, the effects on low-density lipoprotein cholesterol and the body mass index were −0.60 and −0.29, respectively, with p = 0.06 each. While this study strengthens the evidence that the consumption of millets contributes to reducing the risks of hyperlipidaemia, and therefore cardiovascular diseases, more detailed and rigorous studies are recommended.

Can Millet Consumption Help Manage Hyperlipidemia and Obesity?: A Systematic Review and Meta-Analysis

Many health benefits of millets (defined broadly to also include sorghum) have been advocated, including their roles in managing and preventing diabetes; however, the effects of millets on hyperlipidemia (high lipid levels) have been underrecognized. A systematic review and meta-analysis were conducted to collate available evidence of the impacts of millets consumption on lipid profile, namely total cholesterol (TC), triacylglycerol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and very-low–density lipoprotein cholesterol (VLDL-C). The results from 19 studies showed that the consumption of millets for periods as short as 21 days to 4 months reduced levels of TC, triacylglycerol, LDL-C, and VLDL-C (p<0.01) by 8.0, 9.5, 10 and 9.0%, respectively. Four studies demonstrated that millets consumption brought TC and triacylglycerol levels to the normal levels (<200 and <150 mg/dl, respectively). Furthermore, upon consumption of millet-based meals, there was a 6.0% increase in the HDL-C 4.0 and 5.0% reduction in systolic and diastolic blood pressure, and 7.0% reduction in body mass index (BMI). This evidence, leads us to conclude that consumption of millets reduces hyperlipidemia and hence hypertension, and raises the levels of HDL-C (good cholesterol), which can be beneficial for managing the associated risk of developing hypertension and atherosclerotic cardiovascular diseases in future.

Systematic Review Registration: The protocol of this systematic review has been registered in the online registration platform called “research registry” with the unique identification number “reviewregistry1123.”

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.