Effect of Substituting Wheat Flour With Protein-Rich Sources on Quality of Instant Noodles

There is a lack of dietary fiber and some essential amino acids in instant noodles. Enriching this popular food with protein- and fiber-rich sources is important to improve the nutritional quality of noodles. The current study is aimed at enriching instant noodles by substituting wheat flour with lentil flour (7%–35%: L7%, L21%, and L35%), soy-protein isolate (1%–5%: S1%, S3% and S5%), egg-white protein (1–5: E1%, E3%, and E5%) and Spirulina platensis (1%–5%: S.p1%, S.p3% and S.p5%). The physicochemical, microbial, textural, and sensorial properties of noodle samples were investigated. The spatial relationship between parameters was also evaluated based on principal component analysis (PCA) to select the suitable noodle formulation. The highest protein (17.06%) and lowest carbohydrate contents (76.44%) were for L35%. The lowest (1.69%) and highest fat contents (2.04%) were for S5% and S.p5%m, respectively (p > 0.05). Energy values varied from 394.83 (E5%) to 396.37 kcal/100 g (S.p5%). There was no significant difference between the microbial quality of noodle samples (p > 0.05). The hardness of noodles with 1%–5% soy protein, 21% or more lentil flour, and 3% or more egg-white/Spirulina was higher than the control/unenriched group (p < 0.05). The color difference of E1 and E3% with the control sample was not obvious (ΔE^∗ < 3). Although all the ingredients improved the nutritional value of the noodles, the overall acceptance of samples with 3% or more of Spirulina was lower than the acceptable limit (a score of 3). According to PCA, when the nutritional value and sensory acceptance are important, the L35% may be a better choice. E1%, E3%, S1%, S5%, and L7% noodles received almost the same sensory score as the control sample, while they had more nutritional values. A combination of animal, plant, and microalgae protein sources may provide a noodle with high nutritional value, containing a wide range of essential amino acids and bioactive compounds. More research is needed to optimize such a formulation.