Extraction and Comprehensive Characterization of Starch From Ryegrass ( Lolium multiflorum L.) Seeds as a Non‐Conventional Source

ABSTRACT Our research group focused on natural, but unexploited starches, specifically ryegrass seed starch, which was obtained using aqueous (AE) and reducing (RE) extraction. The physical‐chemical, structural, morphological, rheological, and nutritional properties were evaluated. RE starch showed a higher yield (37.81%) compared to AE (31.55%) and exhibited higher luminosity and transmittance, making it the clearest sample. AE starch exhibited a mean particle size ( D 50 ) of 6.95 ± 0.08 µm, whereas RE starch showed a mean particle size ( D 50 ) of 7.54 ± 0.07 µm. Both starches presented small variations among samples and an irregular trimodal particle size distribution. The apparent amylose content of RE starch (17.25%) was higher than AE. RE starch exhibited greater solubility with increasing temperature, reaching a maximum of 7.27 g of gel/g of sample. The highest swelling power (2.56%) was observed in RE starch. RE extraction also resulted in a higher paste temperature (95°C) and greater retrogradation tendency (2954 mPa.s). The highest syneresis occurred at 48 h, with AE and RE showing 24.20% and 27.58%, respectively. RE starch increased both rapidly and total starch digestibility, while slowly digestible and resistant starch fractions, as well as the glycemic index, remained unaffected.