Impact of Glycemic Index and Antioxidant Activity on Human Health of Barnyard Millet-based Designer Vermicelli

Millets are considered “Nutri cereals” because of their abundance of B vitamins, calcium, iron, potassium, magnesium, zinc, dietary fibre and antioxidants. The wonder grains, which are thought to be superior to cereals helps to reduce malnutrition and serious mineral deficiencies (Saini et al., 2021). Antioxidants are bioactive substances that contain the phenolic compounds like tannins, flavonoids and phenolic acids, Carotenoids, ascorbic acid, alkaloids, chlorophyll derivatives, amino acids and amines act as nitrogen compounds, Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (Divya and Garg, 2024). The intake of antioxidant-rich foods helps to regulate blood pressure, diabetes, heart disease and other health conditions. Millet can serve as a therapeutic food with miraculous health advantages (Amadou, 2022).
       
Barnyard millet (Echinochloa frumentacea) is the fastest growing of all the millets and under favourable moisture and temperature conditions Barnyard millet is one of the hardiest millets, which is otherwise known as Japanese barnyard millet, Sanwan, Kuthiravaali and Kavadapullu Ooda, Oadalu and Sanwank. Barnyard millet, a nutritious grain contains a protein of 12 per cent with high digestibility (81.13 per cent) coupled with carbohydrate of 58.56 per cent with slow digestibility (25.88 per cent). Barnyard millet is a minor millet that contains various good sources of micronutrients and phytochemicals like alkaloids, phenols, flavonoids, tannins, terpenoids and saponins (Renganathan et al., 2020).
       
Barnyard millet, which has excellent nutritional, antioxidant, antimicrobial and medicinal benefits, can be used to create novel products that will be more appealing to consumers (Chandraprabha et al., 2017). Consuming barnyard millet-based value-added products helps to address several health issues, including diabetes, obesity, cardiovascular disease, hypertension, ageing and celiac disease. It is possible to think about barnyard millet as a nutritious food that promotes good health.
       
Consumer’s interest towards functional food has increased and nowadays people are more interested in foods fortified with functional ingredients (Day et al., 2009). The functional ingredients like fenugreek (Trigonella foenum - graecum) seeds, garden cress (Lepidium sativum) seeds, Brahmi (Bacopa monnieri) leaves and Ekanayakam (Salacia reticulata) root bark with antioxidant properties, antidiabetic, anticarcinogenic, antibacterial, hypocholesterolemic and hypoglycemic properties were used to develop a convenient product (Wani and Kumar, 2015b; Yadav, 2014; Yoshino et al., 2009). 
       
Designer vermicelli made from barnyard millet and a range of functional ingredients can be utilized as a potential vehicle to deliver nutraceutical qualities (Goel et al., 2021; Kaur et al., 2024). This research aims to examine the antioxidant and glycemic index of prepared barnyard vermicelli supplemented with beneficial additives for human health.

Barnyard millet-based designer vermicelli was formulated by using germinated barnyard millet flour, whole wheat flour and functional ingredients (fenugreek seeds flour, garden cress seed flour, Brahmi leaves powder and Ekanayakam root bark) to evaluate its acceptability and health qualities.
 
Preparation of barnyard millet flour and functional ingredients
 
Barnyard millet was cleaned, washed and soaked in water for 10 hours, with a water change every 2 hours. The surplus water was drained and the seeds germinated for 24 hours under a damp cloth. The seeds were dried in a hot air oven at 65 degrees Celsius. Devegetated seeds were pulverized and sieved through a 40 mesh sieve.
       
Fenugreek seeds were cleaned, washed and steeped in water for 12 hours, with six-hour water changes. The seeds were dried at 65 degrees Celsius, pulverized and sieved through a 40-mesh sieve after 24 hours of germination to achieve uniform flour. Garden cress seed and Ekanayakam root bark were dried at 65 degrees Celsius, powdered and sieved through a 40-mesh sieve to form fine flour. Brahmi leaves were dried at 65 degrees Celsius to a moisture level of less than 10 per cent, pulverized and sieved through a 40 mesh size to obtain a uniform powder.
 
Preparation of barnyard millet vermicelli incorporated with functional ingredients
 
Millet based vermicelli was prepared by adapting the standard procedure of Renganathan et al., (2020). The treatment T0 was vermicelli prepared using refined wheat flour, served as control. Treatments T1 to T4 were prepared using germinated barnyard millet flour incorporated with different proportions of ingredients used as given Table 1. Brahmi (Bacopa monnerei) incorporation at the level of 0.5 g was shown to be superior in terms of sensorial quality (Zaker et al., 2014).


 
Organoleptic analysis
 
The acceptability evaluation of the prepared barnyard millet vermicelli and uppuma recipe was carried out by a well-trained panel of 15 judges. The quality parameters like appearance, colour, flavour, texture, taste and overall acceptability were analysed by a panel of judges.

Health studies
 
Total antioxidant activity
 
Antioxidant capacity of the barnyard millet based functional ingredient vermicelli extract was measured using DPPH (1’1- diphenyl-1-picryl hydrazine) spectrometric assay as suggested by research of Blois (1958). The Methanolic solution containing DPPH radicals (0.1 mM) was added to the sample at varied concentrations and the mixture was violently agitated. The reaction mixture was left in the dark for 30 minutes. In a spectrophotometer, the absorbance was measured at 517 nm. Using the following formula, the percentage of antioxidant activity was calculated.
 

  

                                                                       
The graph of the percentage of radical scavenging activity against sample concentration was used to determine the sample concentration that would inhibit an enzyme by 50% (inhibitory concentration - IC50).
 
Glycemic index
 
A glucose tolerance test is a glucose loading test to understand the function of islet beta cells and the body’s ability to regulate glucose. The five healthy people were given the barnyard millet-based designer vermicelli and control food to test its glycemic reaction and the glycemic index was calculated using a formula suggested by Srilakshmi (2011). Glucometers are used to carry out this test. Initially, a glucose tolerance test was performed to identify the healthy patients. The respondents were instructed to stop taking all medications at least three days before to the test and to keep an eight-hour fast. A measurement of the fasting blood glucose was made. By giving barnyard millet-based uppuma recipe to each subject and comparing the results to the control, the postprandial glucose level for each subject was determined. A similar amount of the test food was consumed alongside 75 g of glucose. At specified time intervals of 30 minutes up to 2 hours after the food load, the blood glucose levels were measured. The glycemic index of the barnyard millet uppuma were computed from the observation recorded with the formula as follows.
 

                                  

 
Quality evaluation
 
Health studies like antioxidant activity and glycemic index for barnyard millet-based vermicelli were done initially, second and fourth months after storage.

Table 2 and 3 display the test results for the taste and flavour of barnyard millet vermicelli and uppuma with functional ingredients added. According to the findings of the study, barnyard millet vermicelli (T1) prepared with 40 per cent barnyard millet, 58 per cent whole wheat flour and 2 per cent fenugreek seed flour was highly acceptable in terms of appearance, flavour, texture and taste; treatment T4 prepared with 40 per cent barnyard millet, 58 per cent whole wheat flour and 2 per cent Ekanayakam root barks was highly acceptable in terms of colour. The fenugreek seed-infused barnyard millet-based designer vermicelli received a mean acceptance score of 7.77, while the garden cress received a score of 7.88. In Treatment T1, the lowest colour values decrease the overall acceptability of the product.



​
       
The barnyard millet uppuma fortified with functional ingredients treatment T1 prepared with a proportion of 40 per cent barnyard millet, 58 per cent whole wheat flour and 2 per cent fenugreek seed flour was highly acceptable in terms of flavour and texture. The treatment T2 barnyard millet based uppuma fortified with garden cress seed flour in combination of 40 per cent barnyard millet, 58 per cent whole wheat flour and 2 per cent garden cress seed flour was highly acceptable, with a mean score in terms of appearance (8.40), colour (8.24), taste (8.06) and overall acceptability (8.31).
       
The antioxidant activity of barnyard millet-based vermicelli incorporated with functional ingredients was higher than the control, as represented in initially, the antioxidant activity of vermicelli made from barnyard millet ranged from 23.28 to 27.18 per cent, with T1 (fenugreek-based vermicelli) having the highest antioxidant activity and T4 (Ekanayakam-based vermicelli) having the lowest antioxidant activity (Table 4). The antioxidant activity of the vermicelli gradually decreased during the second month of storage, we observed that T1 had the highest antioxidant activity (26.98 per cent) and T4 had the lowest antioxidant activity (23.09 per cent). During the fourth month of storage, the antioxidant activity of the vermicelli ranged from 22.94 per cent (T2) to 26.74 per cent (T1). Control (T0) had the lowest antioxidant activity of all the vermicelli, starting at 13.68 per cent and falling to 13.37 per cent by the end of storage. Over the entire storage period, a significant difference was observed in all treatments. According to Devi and Nazni (2016), barnyard millet flour exhibited a greater level of antioxidant activity compared to other millets. In addition, they developed chapatti made from barnyard millet, which exhibited an antioxidant activity ranging from 47 to 53 per cent. Daret_al(2016) found that after 6 months of storage, the antioxidant activity of bran-enriched extruded snacks decreased from an initial value of 38.99 per cent to 32.15 per cent. Wani and Kumar (2016) and Sharma and Riar (2020) observed a similar trend of antioxidant decreases in storage.

​
       
The five non-diabetic responders were given the equivalent of 75 g of carbohydrate-rich test food carbohydrates. The glycaemic index of barnyard millet-based vermicelli incorporated with functional ingredients was given in Table 5. The control had the highest glycaemic index when compared to other barnyard millet-based vermicelli. The Treatment T3 (Brahmi leave based barnyard vermicelli) had the lowest glycemic index of 48.25, followed by T1 (55.65), T2 (56.40) and T4 (57.51). The glycemic index varied significantly across each treatment; however, T1 was comparable to T2.  According to a study conducted by Ugare et al., 2014 revealed that intake of dehusked and heat-treated barnyard millet has a beneficial effect in reduction of blood glucose level. The antioxidant activity of brahmi (bacoside A and bacoside B) greatly influence the stability of the glycemic index (Charoenphon et al., 2016; Shankar et al., 2018).

​

The present study revealed that barnyard millet is an underutilized grain that can be effectively used in the development of millet-based designer vermicelli incorporated with functional ingredients (2 per cent germinated fenugreek seed flour/garden cress seed flour/ Ekanayakam root barks powder and 0.5 per cent Brahmi leave powder). The barnyard millet-based vermicelli prepared with the addition of functional ingredients showed high antioxidant activity and low glycemic index in comparison with control. The designer vermicelli was observed to have good sensory, nutritional and health qualities.

No conflict of interest amongst the authors associated with this work.