Effects of sweet potato leaf powder on sensory, texture, nutrition, and digestive characteristics of steamed bread

Abstract

This study investigated the influence of sweet potato leaf powder (SPLP) (0%–16%) on steamed bread quality. Results showed with the addition of SPLP, height/diameter ratio increased from 0.44 to 0.96, specific volume decreased from 2.44 to 1.47, color changed from white to dark green, and hardness, gumminess, and chewiness ascended gradually; the contents of protein, fat, dietary fiber, minerals, vitamin B2, and niacin increased significantly, in particular, the polyphenol content increased from 1.34 to 9.34 mg chlorogenic acid equivalent/g DW, and the antioxidant activity increased from 1286.08 to 5650.77 μg ascorbic acid equivalent/g DW; the carbohydrate content decreased from 77.60 to 71.50 g/100 g DW, and the estimated glycemic index decreased from 95.25 to 87.51. The steamed breads with 2%–10% SPLP were overall acceptable. In conclusion, adding appropriate quantity of SPLP to wheat flour will not only maintain the technological quality but also improve the nutritional value of steamed bread. Practical applications In recent years, the effective development and utilization of sweet potato leaf (SPL) has become an urgent problem to be solved. The nutritive value of traditional wheat steamed bread are often difficult to meet the daily health needs of human beings. SPL is known to be a rich source of nutrients and bioactive compounds. The application of SPLP in the production of steamed bread is an innovative method with low cost and environmental protection. Therefore, this study aimed to improve the nutritional and functional value of steamed bread by the application of SPLP.

Effects of dietary fibres, polyphenols and proteins on the estimated glycaemic index, physicochemical, textural and microstructural properties of steamed bread

“…The above results were consistent with the study by Hu et al (2022b), who found that dietary fibre, polyphenols and protein contents in steamed bread were significantly increased after different proportions of sweet potato leaf powder were added, while the specific volume decreased and the height-to-diameter ratio increased. Similarly, Wang et al (2021) and Crockett et al (2011) found that the specific volume of steamed bread and gluten-free bread decreased with the increased addition of insoluble dietary fibre, ferulic acid and soybean protein isolate.…”

“…The above results were consistent with the study by Hu et al . (2022b), who found that dietary fibre, polyphenols and protein contents in steamed bread were significantly increased after different proportions of sweet potato leaf powder were added, while the specific volume decreased and the height‐to‐diameter ratio increased. Similarly, Wang et al .…”

“…Previous studies also indicated that adding higher amounts of dietary fibres (sweet potato dietary fibre, pomelo peel dietary fibre, oat fibre), polyphenols (proanthocyanidin, catechin, curcumin) and proteins (glutenin, soybean protein isolate, rice protein) to bread or steamed bread resulted in a denser microstructure and lower porosity (Ortiz de Erive et al ., 2020; Sardabi et al ., 2021; Xue et al ., 2021; Yesica et al ., 2021; Sang et al ., 2022; Hu et al ., 2022a; Hu et al ., 2022b). The water adsorption capacity of dietary fibre was much higher than that of proteins, it could competitively bind more water molecules than the gluten in wheat flour, making the secondary structure among the gluten molecules become weak and easy to be damaged and eventually leading to the reduction of porosity (Xin et al ., 2022).…”

The Chemical, Rheological, and Sensorial Characteristics of Arabic Bread Prepared from Wheat-Orange Sweet Potatoes Flour or Peel

“…Under the same preparation and baking conditions, the change in color is closely related to the overall contents of the product, especially from elements, pigmented phytochemicals, and precursors of the Maillard reaction [ 94 ]. Furthermore, the increase in fiber and polyphenols could affect the elasticity of dough, thus the texture, roundness, and chewability of the final product [ 84 , 95 ]. These factors combined might contribute to the overall evaluation of the bread.…”

Changes in Pectin Composition and Structure During Thermomechanical Treatment and Their Intrinsic Relationship with the Quality of Purple Sweet Potato Puree

“…After the optimal process parameters were determined, the proximate composition of fresh PSP and PSPP was analyzed; among which, the moisture was determined according to GB5009.3–2016, starch was evaluated as described by GB5009.9–2023, total dietary fiber was determined according to GB5009.88–2023, ash was determined according to GB5009.4–2016, fat was determined as described by GB5009.6–2016, and protein was determined via Kjeldahl method and calculated with a nitrogen conversion factor of 6.25 …”