People residing in Eastern, Central Europe and Asia prefer commercially made noodles in routine diet. Contingent upon the regional custom, noodles are eaten as valuable supplements as well as staple food. Wheat flour (WF) is typically used for preparation of noodles because of specific networking proteins known as gliadin and glutenin that impart cohesive and an elastic structure of dough during kneading (Cappelli, Oliva, & Cini, 2020). Nevertheless, noodle preparation only from WF in not adequate in perception of nutrition balance due to insufficient amounts of minerals and vitamins (lysine) (Guardianelli, Salinas, & Puppo, 2019). Furthermore, wheat products are restricted in individuals who suffered from diabetes and cardiovascular disease due to extensive elevation of glucose concentration in blood level (Liu, Zhao, Wang, & Liu, 2019). Celiac disease is recognized as a heredity autoimmune illness that substantially impacts on the digestion capacity of small intestine. Furthermore, CD is common in countries where staple food of the people is wheat. CD induces the initiation of infertility, osteoporosis, autoimmune disorder whereas in rare cases cancer. The most effective therapy for CD is the consumption of gluten free diet in entire span of life, resulting in clinical and mucosal recovery was observed (Briani et al., 2008).

However, the root crop recognized as sweet potatoe (Ipomoea batatas L.) sustains wide range of qualities, including rich nutritional value, ability to adapt marginal conditions, minimum production cycle and sensory variety due to different flesh attributes (Azeem, Mu, & Zhang, 2019). In the meantime, sweet potatoes are an important part in the traditional diet around the globe due to abundant dietary fiber, low fat and variety of micronutrients and phytochemicals. From different cultivars, orange fleshed sweet potato recognized as biofortified, differs in perspective of a rich source of carotenoids especially β-carotene which possess strong antioxidant activities due to conjugated double bonds in its structure (Melendez-Martınez, Britton, Vicario, & Heredia, 2007).

Sweet potato is abundantly utilized in the food industry for starchy, and other concomitant products preparation. During processing the main problem is browning that is induced by the enzymatic and non-enzymatic reaction. Non-enzymatic reaction recognized as Maillard reaction that occurred at high temperature between amino acids and reducing sugar, whereas enzymatic reaction happened at low temperatures owing to peroxidase and oxidation of phenol by polyphenol oxidase (Graham-Acquaah, Ayernor, Bediako-Amoa, Saalia, & Afoakwa, 2014).

In order to overcome the above problems, pre-treatment by soaking in different solutions such as citric acid and sodium metabisulphite are already investigated (Ahmed, Akter, & Eun, 2010; Kuyu, Tola, Mohammed, & Ramaswamy, 2018). Traditional thermal processing significantly alters the structure of bioactive compounds, alongwith declines in other quality characteristics. In recent years, high hydrostatic pressure (HHP) that's is non-thermal processing technology gained much acclaim in food industry, possibly owing to alternation of biopolymer structure, prevention of color loss and inactivation of endogenous enzymes, etc. (Peng et al., 2016). HHP technology has already been used for the production of various food items, such as hydrated oat, finger millet and sorghum flours, quinoa flour, wheat dough and bread (Angioloni & Collar, 2012; Bárcenas, Altamirano-Fortoul, & Rosell, 2010; Zhu & Li, 2019) Some studies have already been conducted in prospect to the utilization of SPF for noodles preparation (Menon, Padmaja, & Sajeev, 2015; Yadav, Yadav, Kumari, & Khatkar, 2014). Furthermore, limited information about the effects of soaking solution and high hydrostatic pressure on gelatinization properties of flour and antioxidant activity alongwith in vitro- digestibility of β-carotene in sweet potato noodles is currently available.

The objective of the present study was to elucidate the effect of soaking solution and high hydrostatic pressure on in vitro digestibility of β-carotene in gluten free sweet potato noodles.