Comparison of functional and structural properties of ginkgo seed protein dried by spray and freeze process

Preparation and functional characteristics of protein from Ginkgo endophytic Pseudomonas R6 and Ginkgo seed

Ginkgo seed protein (GSP) has excellent processing characteristics and antioxidant properties. In this study, Gingko endophytic protein (GEP) was synthesized by Ginkgo endophytic Pseudomonas R6. SDS-PAGE analysis indicated that the molecular weights of GSP and GEP were mainly distributed at 17 KDa and 48 KDa, respectively. FTIR showed that GEP and GSP exhibited characteristic absorption in the amide I, II, and III bands, and absorption in amide A and B indicated the presence of hydrogen bonding. HPLC analysis showed that both proteins had 17 amino acids, but their relative abundance was different, with GSP having the highest Ser content (74.713 mg/g) and GEP having the highest Val content (35.905 mg/g). Stomata were observed on the surface of both proteins by SEM, and there were lamellar and some spherical structures on GEP, while the opposite was observed on GSP. GEP had superior solubility, OHC, FC and EC, while GSP showed good WHC. Both proteins exhibited antioxidant activities, with GSP exhibiting stronger hydroxyl radical scavenging ability than GEP, with IC50 of 0.46 mg/mL and 1.54 mg/mL, respectively. This work demonstrates the antioxidant potential of GEP as an alternative to GSP in the food industry.

A review on the hydration properties of dietary fibers derived from food waste and their interactions with other ingredients: opportunities and challenges for their application in the food industry

Dietary fiber (DF) significantly affects the quality attributes of food matrices. Depending on its chemical composition, molecular structure, and degree of hydration, the behavior of DF may differ. Numerous reports confirm that incorporating DF derived from food waste into food products has significant effects on textural, sensory, rheological, and antimicrobial properties. Additionally, the characteristics of DF, modification techniques (chemical, enzymatic, mechanical, thermal), and processing conditions (temperature, pH, ionic strength), as well as the presence of other components, can profoundly affect the functionalities of DF. This review aims to describe the interactions between DF and water, focusing on the effects of free water, freezing-bound water, and unfreezing-bound water on the hydration capacity of both soluble and insoluble DF. The review also explores how the structural, functional, and environmental properties of DF contribute to its hydration capacity. It becomes evident that the interactions between DF and water, and their effects on the rheological properties of food matrices, are complex and multifaceted subjects, offering both opportunities and challenges for further exploration. Utilizing DF extracted from food waste exhibits promise as a sustainable and viable strategy for the food industry to create nutritious and high-value-added products, while concurrently reducing reliance on primary virgin resources.

Preparation and characterization of octenyl succinic anhydride-modified ginkgo seed starch with enhanced physicochemical and emulsifying properties

A quick preparation of octenylsuccinylated (OS)-ginkgo seed starch was proposed by lipase-coupling esterification within 30 min, and the physicochemical and emulsifying properties of OS-ginkgo seed starch were evaluated. High-performance liquid chromatography results revealed that ginkgolic acid in ginkgo seed starch was too low to be detected, which improved the biosafety and application range of OS-ginkgo seed starch. The degree of substitution (DS) of OS-ginkgo starch varied from 0.006 to 0.0169 depending on the lipase concentration increased from 0% to 1% (w/w, based on the volume of starch solution), and the reaction efficiency obtained the highest value of 68.5% at the lipase concentration of 1%. Fourier transform infrared spectra of OS-ginkgo seed starch confirmed ester carbonyl splicing in the starch molecular with the characteristic peaks at 1722 and 1567 cm^-1 . Scanning electron microscopy observations revealed that the esterification occurred mainly in the amorphous regions with slight morphological modification. X-ray diffractions suggested that no crystal change occurred on the starch granule. The thermal analysis revealed that OS-ginkgo seed starch showed a lower temperature and endothermic enthalpy for gelatinization, and presented enhanced and DS-dependent emulsifying properties and in vitro antidigestion properties. PRACTICAL APPLICATION: Results indicated that OS-ginkgo seed starch prepared by lipase-coupling esterification would be an alternative emulsion stabilizer for encapsulation and delivery of hydrophobic components. This study would provide an alternative method for the efficient and economical production of OS-ginkgo seed starch, thereby broadening its application in commercial exploitation.

Physicochemical, Functional, and In Vitro Digestibility of Protein Isolates from Thai and Peru Sacha Inchi (Plukenetia volubilis L.) Oil Press-Cakes

Proteins from Sacha inchi (SI) have been widely known for their health-benefiting properties. This study aimed to investigate the different protein isolates obtained from oil press-cakes of Thai and Peru SI. The protein content and protein recovery of Thai and Peru SI were estimated to be 93.27, 90.67%, and 49.15, 59.32%, respectively. The protein patterns of the Thai and Peru SI samples analyzed by SDS-PAGE showed glycoprotein as a major protein, with a molecular weight of 35 kDa. Both protein isolates (PI) showed water and oil holding capacities in the range of 2.97−3.09 g/g sample and 2.75−2.88 g/g sample, respectively. The emulsifying properties of the PI from Thai SI were higher than those of Peru (p < 0.05), while the foaming properties were not analogous to the emulsion properties. The Thai SI sample showed lower digestibility up to 120 min of in vitro digestion time than that of the Peru SI sample (p < 0.05). However, simulated in vitro pepsin digestion of Thai and Peru Si samples displayed hydrolyzed protein bands compared to trypsin digestion, which showed no protein patterns in both SI samples on a 4−20% gradient gel. These results suggest that the protein isolates from Thai and Peru SI exhibit marked variations in physical and techno-functional properties and have a high potential to be employed as plant-based protein additives for future non-animal-based protein-rich foods.

Ginkgo Seed Proteins: Characteristics, Functional Properties and Bioactivities

Ginkgo biloba L. is an ancient plant relic, which is known as a "living fossil", and is widely cultivated in China. This plant with medical potential and health benefits has drawn the attention of researchers. Ginkgo seeds are rich in protein. Ginkgo seed proteins (GSPs) have good functional properties over many other seed proteins, which have the potential to be utilized as food ingredients. Moreover, GSP contains no restricted amino acids and is easy to be separated. Several GSP isolate with various bioactivities, such as antimicrobial and antioxidative activities, have been purified and evaluated for their bioactive potential. In this review, the separation methods and bioactivities of GSP were summarized, physicochemical characteristics and functional properties were comprehensively reviewed and compared with other seed proteins. Some food applications of GSP were also briefly introduced. Besides, some suggestions and prospects were discussed in this review.