Characterization of fruit pulp-soy protein isolate (SPI) complexes: Effect of superfine grinding.

Superfine grinding (SG), as an innovative technology, was conducted to improve the physicochemical and structural properties of fruit pulps. Nectarine, apple, and honey peach were selected as the materials. With the increase in SG frequency, the soluble solids content, viscosity, D[4, 3], D[3, 2], G' and G″ of fruit pulps were evidently decreased, whereas the turbidity was increased. The smallest D[4, 3] (294.90 µm) and D[3, 2] (159.67 µm) were observed in nectarine pulp under SG at 50 Hz. The highest turbidity (266.33) was shown in honey peach pulp under SG at 50 Hz. The active groups of the fruit pulps with SG were exposed by Fourier transform infrared spectroscopy (FT-IR). Notably, the excessive destruction in structure was confirmed in SG with 50 Hz. With soy protein isolate (SPI) addition, D[4, 3] and D[3, 2] of complexes decreased, whereas G' and G″ increased. The formation of new fruit pulp-SPI complexes was demonstrated by FT-IR and LF-NMR analysis. The dense and uniform structure was found in complexes prepared by SPI and fruit pulp with 30 Hz SG. Especially, apple-SPI complex with 30 Hz SG showed the highest water-holding capacity (WHC) (0.75) and adhesiveness (7973.00 g s). A significant correlation between fruit pulps and the complexes was revealed. Taken together, the impact of SG modification on fruit pulps would enhance WHC, rheology, and textural properties of the fruit pulp-SPI complexes, especially for SG with 30 Hz. PRACTICAL APPLICATION: This research provided a comprehensive exploration of the potential of SG technology to modify fruit pulps, solving the diversity of textural customization problems and offering valuable insights for the development of semisolid food products.

Effect of peach puree incorportion on cookie quality and on simulated digestion of polyphenols and antioxidant properties.

The aim of this work was to identify and quantify the bioaccesible phenolic compounds and evaluate their relationship with the antioxidant properties of three different cookies formulated with 10.5% peach pulp incorporation and 50% fat or added-sucrose reduction. Peach pulp and dietary fiber were incorporated in cookie formulation and two levels of fat or sucrose were analyzed. Cookie quality was modified by fruit incorporation and reduction of fat and added-sucrose. Fruit incorporation changed the polyphenol profile and improved antioxidant properties. Most phenolic compounds quantified in both the extracts and the different stages of the simulated digestion were higher in the sucrose/fat reduced samples than in the control samples, which represents a nutritional improvement of the pulp-enriched cookies. Evaluation of the bioaccessibility of polyphenols from cookies showed that a fraction of polyphenol could be absorbed by the small intestine. This fraction ranged between ~21% and ~25%, according to the sample.

Comparison Study on Determination of Trace Element Content in Peach Pulp between Wet Digestion Method and Carbonize Acid Dissolution Method / 世界科学技术-中医药现代化

This study was aimed to determine trace elements in Peach pulp . The wet digestion method and car-bonize acid dissolution method were applied to digest the sample, and flame atomic absorption spectroscopy was used to determine the content of trace elements (Fe, Cu, Mn) in Peach pulp . The results showed that the content is not consistent among different pretreatment methods. However, the metalion content among these three methods are in the order of Fe > Mn > Cu, with the average recovery rate between 92.6% and 119.6%. The RSD is less than 2.86%. It was concluded that this method is with high accuracy and stability as well as reliable accurate re-sults. It also proved that Peach pulp . is rich in Fe, Cu and Mn. It provides some useful information for further pharmacological study of Peach pulp .