Morphology, structure and in vitro digestibility of starches isolated from Ipomoea batatas (L.) Lam. by alkali and ethanol methods

Characteristics of physicochemical properties, structure and in vitro digestibility of seed starches from five loquat cultivars

Starch plays a pivotal role in food and other industries, necessitating the exploration of new starch sources to cater the substantial requirement. This study delved into the variations in the physicochemical properties, structure attributes and in vitro digestibility of seed starches extracted from five distinct loquat cultivars (Eriobotrya japonica L.). The starch extraction yield of loquat seeds was found to be 45.2 % as an average. Loquat seed starches were designated as having high-amylose starch (>50 %). The starch granules exhibited similar shapes, but granular size significantly varied across the cultivars. Loquat starches presented a C-type crystalline pattern with relative crystallinity from 17.14 % to 21.06 %. The short-range ordered structure of the starches differed with loquat cultivars. The swelling power, solubility and amylose leaching of loquat starches increased with increasing temperature, significantly varying among different cultivars. Gelatinization parameters exhibited significant variations among the loquat starches. Different loquat starches exhibited pronounced variations in paste clarity, water and oil absorption capacity. Marked differences were detected in proportions of rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) across the five cultivars, with RS being particularly prominent fraction with an average of 84.30 %. These compressive findings offer valuable insights into the potential application of loquat seed starches in the formulation of foods and various industrial products.

Structural and Physicochemical Properties of Tunisian Quercus suber L. Starches for Custard Formulation: A Comparative Study

The aim of the present study was to extract starch from acorn (Quercus suber L.) fruits using water and alkaline methods. Structural and functional properties of extracted starches were investigated and compared to those of corn and modified starches in order to determine their innovative potential application in food industry. The yield of extraction using the two methods was about 48.32% and 48.1%. The isolated starches showed low moisture, fat and protein contents, revealing high purity and quality. Additionally, the starch extracted using the alkaline method (AAS) showed higher lightness (60.41) when compared to starch isolated using hot water (WAS). However, the lightest white color was found for studied commercial starches. Moreover, AAS starch exhibited the highest swelling power, solubility and water absorption, followed by WAS and commercial starches. Results showed that extracted acorn starches were characterized by greater enthalpy and gelatinization temperatures. Similar observations were noted using FT-IR spectra analysis for all analyzed starches. In addition, granule starches observed using scanning electron microscopy were found to be spherical and ovoid. However, from the analysis by X-ray diffraction, a crystalline pattern of C-type was found for acorn starches, while commercial starches presented an A-type pattern. As an innovative food application, these underexploited acorn starches were valued and served to produce new custards with improved functional properties and better microstructure when compared to commercial custard.

Physicochemical and structural characterization of starches from Andean roots and tubers grown in Colombia

The preservation of Andean roots and tubers (ART) depends on the recognition of their health-promoting and nutritional metabolites and their transformation into other products such as starches. The objective of this study was to determine the physicochemical and structural properties of native starches obtained from Canna edulis K., Oxalis tuberosa M., and Ipomoea batatas L. from the Colombian Andean agroecosystem. The physicochemical properties of starches were determined by traditional methods of analysis. The thermal properties were determined by gravimetric thermal analysis (TGA) and differential scanning calorimetry (DSC), while the structural characteristics were studied with X-ray diffractometry and infrared spectrometry. The ART showed a starch yield of between 53.3% and 75.4% (dry basis) and amylose content between 28.4% and 35.6%. Starches from I. batatas showed the highest percentage of amylose, lowest gel clarity, lowest water absorption index, and highest gel temperature. X-ray diffractograms showed a type A crystallographic pattern for I. batatas starch, and a type B pattern for C. edulis and O. tuberosa starches, while infrared spectra (FTIR-ATR) corroborated the structural characteristics of each type of starch. The results suggest that starches from Andean resources can be used as a substitute for traditional starches from corn and potato. In addition, their amylose content makes them potential sources of resistant starch and dietary fiber.