Polysaccharides are the main bioactive components in safflower. In this study, safflower polysaccharides (SPs) were extracted by ultrasonic assisted extraction, and four purified safflower polysaccharide fractions (named SSP1, SSP2, SSP3, and SSP4, respectively) were obtained. The physicochemical properties and in vitro physiological activities of the four fractions were investigated. The molecular weights (M_W) of the SSPs were 38.03 kDa, 43.17 kDa, 54.49 kDa, and 76.92 kDa, respectively. Glucuronic acid, galactose acid, glucose, galactose, and arabinose were the main monosaccharides. The Fourier transform infrared spectroscopy (FT-IR) indicated that the polysaccharides had α- and β-glycosidic bonds. Nuclear magnetic resonance (NMR) analysis showed that SSP1 had 6 different types of glycosidic bonds, while SSP3 had 8 different types. SSP3 exhibited relatively higher ABTS⁺ scavenging activity, Fe⁺³-reduction activity, and antiproliferative activity. The results will offer a theoretical framework for the use of SPs in the industry of functional foods and medications.

Polysaccharides are important bioactive components of Nitraria retusa fruit (NRF). In this study, the ultrasonic-assisted extraction (UAE) conditions of polysaccharides from Nitraria retusa fruit (NRFPs) were optimized by response surface methodology (RSM). The structural characteristics and antioxidant activity were investigated. The maximum NRFPs yield of 3.35% was obtained under the following optimal conditions: temperature of 59.5 °C, time of 30.5 min, liquid-to-solid ratio of 19.5 mL/g. Three polysaccharide fractions, NRFP-1 (20.01 kDa), NRFP-2 (28.96 kDa), and NRFP-3 (67.45 kDa), were isolated. Glucose, galactose, and arabinose in different percentages were identified as the primary monosaccharide units. The Fourier transform infrared spectrometer (FT-IR) and nuclear magnetic resonance (NMR) analysis indicated the presence of α- and β-glycosidic bonds in NRFPs. The NRFP-3 exhibited the highest scavenging activities against DPPH, ABTS, -OH free radicals, and Fe⁺³-reducing activity.

To produce products with standardized and optimal technical performance, probiotics, particularly Lactic Acid Bacteria (LAB), have long been utilized as fermentation starters in sausages, ensuring both the standardization and enhancement of product quality and safety. Microorganisms isolated from traditional meat products, due to their excellent adaptability to the fermentation environment and their ability to preserve desirable flavor, exhibit high potential as candidates for meat fermentation starters. Three indigenous LAB strains—Latilactobacillus sakei, Pediococcus pentosaceus, and Weissella cibaria, isolated from Yunnan ham—were applied in the fermentation of beef sausages to investigate the underlying factors responsible for quality changes. The results indicated that sausages fermented with L. sakei and P. pentosaceus exhibited the lowest pH (4.98) and a_w (0.79), while displaying significantly higher hardness, cohesiveness, and chewiness. Additionally, LF-NMR measurements showed that L. sakei and P. pentosaceus promoted the transfer of immobilized water to free water, facilitating the drying and maturation process. Raman spectroscopy analysis revealed a reduction in α-helix content and an increase in disordered β-sheet and β-turn structures in the secondary protein structure. These findings suggest that L. sakei and P. pentosaceus improved quality attributes by modifying the secondary protein structure to enhance water migration and accelerate the ripening process. L. sakei and P. pentosaceus demonstrated desirable technological characteristics, indicating their efficacy for use in fermented sausage production. This study provides valuable insights into improving the production of fermented sausages using specific LAB strains.