Effect of pin‐to‐plate atmospheric cold plasma on technological and nutritional functionality of horse gram (Macrotyloma uniflorum) flour
Authors: Patra Abhipriya , Prasath V. Arun , Shende Ayush Sanjay , Thakur Rahul , Deep BandanaRanee , Madhumathi G. , Sarkar Preetam 
Published: February 2024

Atmospheric cold plasma (CP), an acclaimed nonthermal technology, has gained popularity for its effective microbial inactivation in food materials, concurrently improving functional and nutritional aspects. Despite the nutraceutical benefits, horse gram (Macrotyloma uniflorum) is underutilized in baking and confectionery due to presence of major antinutrients. Our aim is to leverage CP to enhance horse gram's properties, promoting its viability in these sectors. The present study investigates the effect of CP treatment with varying output voltage (10–30 kV) and exposure time (5–25 min) on horse gram flour's nutritional, functional, and antinutritional properties. Moreover, the molecular interactions, crystallinity, thermal stability, and morphological characteristics were analyzed. CP treatment doubled the nutritional properties of horse gram flour and amplified the functional attributes by 1.5 times as compared to untreated flour, but excessively higher voltage (30 kV) and time (15 and 25 min) declined them. Whereas the antinutritional components—tannin, saponin, and phytic acid—were reduced to 1.43 ± 0.01 μg TAE/g, 0.72 ± 0.01 mg diosgenin/g, and 5.26 ± 0.03 mg phytate/g, respectively, after CP treatment, enhancing digestibility of the flour up to 75%. Principal component analysis illuminated the intricate relationship between CP treatment and flour attributes. Both low voltage (10 kV) with moderate exposure (15 and 25 min) and high voltage (30 kV) with shorter duration (5 min) exhibited favorable correlations with physiochemical, bioactive, and functional properties. Conversely, high voltage with prolonged exposure displayed a notable negative correlation with antinutritional properties, structural, and thermal characteristics, revealing the nuanced impact of treatment conditions on the quality of flour. Overall, CP can be recognized as a potential novel technique for the techno‐functional reformation of underutilized food materials.

Practical applications

The horse gram is one of the underutilized crops rather than being a huge source of health and nutritional benefits. On the other hand, cold plasma is a novel technique in food processing which can be used for improvement of structural and functional properties of food products. That is why the purpose of the study not only was to enlighten the nutritional composition of the horse gram flour but also to improvise its techno functional qualities using cold plasma. However, the presence of the antinutrients in the horse gram flour acts as constraints for digestibility. The application of cold plasma on horse gram flour reduced the antinutrients present in it as well as improved the physiochemical and nutritional characteristics significantly. Moreover, the structural characteristics of the flour were affected by cold plasma which increased its stability for longer shelf life. Furthermore, the functionality of the flour was enhanced which showed an opportunity the better dough characteristic, emulsifying properties. These findings would help the usage of the horse gram flour as food ingredients in various bakery and confectionary food applications.