Effects of high hydrostatic pressure on the quality and shelf-life of jujube (Ziziphus jujuba Mill.) pulp

Bound phenolics extracts of jujube peel relieve cadmium-induced toxicity by reducing lipid accumulation of Caenorhabditis elegans

To investigate the effect of bound phenolics extracts (BPEs) of jujube peel on relieving cadmium (Cd)-induced toxicity and its mechanism, the behavioral deficits, lipid accumulation, and fatty acid synthesis-related gene expression in Caenorhabditis elegans in Cd exposure group and BPEs improvement groups were determined and compared. The results showed that BPEs significantly improved Cd-induced behavioral deficits in C. elegans, and no significant differences could be found in low-dose (12.5 µg/mL) and high-dose (100 µg/mL) BPEs improvement groups. The treatment of BPEs effectively improved intestinal injury and lipofuscin and lipid accumulation. Especially, oil red O staining intensity in C. elegans treated with BPEs at 50 µg/mL was reduced by 12.60%. BPEs significantly controlled the increase in content of C16:0, C16:1, C18:0, C18:1, and C18:2 induced by Cd by regulating the lipid accumulation in Escherichia coli OP50. Cd exposure induced lipid accumulation in C. elegans by upregulating oleic acid synthesis-related gene expression in E. coli OP50. Furthermore, BPEs treatment significantly downregulated the fatty acid synthesis-related gene expression in C. elegans and E. coli OP50. This research could reveal the mechanism of BPEs of jujube peel in relieving Cd-induced toxicity and provide a theoretical basis for the development of functional foods rich in polyphenols. PRACTICAL APPLICATION: Jujube peel, a by-product of jujube processing, is usually discarded due to its coarse texture. However, jujube peel has been proven to possess abundant polyphenols, polysaccharides, and cyclic adenosine phosphate. In addition, in our previous research, bound phenolics extracts (BPEs) of jujube peel were found to perform better in lowering lipid accumulation than that of free phenolics extracts. This study further investigate the effect of BPEs of jujube peel on relieving Cd-induced toxicity and its mechanism on the base of our previous research. It could realize the comprehensive utilization of by-products of jujube processing.

Functional Nutrients and Jujube-Based Processed Products in Ziziphus jujuba

Jujube (Ziziphus jujuba Mill.) is the first tree species in China, with a long history and abundant yield. However, fresh jujubes have a short shelf-life and are not resistant to storage. Therefore, more and more processed jujube products are being studied. These processed products can extend the shelf-life of jujubes and attract widespread attention for their rich functional nutrients. This review summarized changes in nutrients of fresh jujube and processed products and the research progress of different preparation methods of jujubes. Meanwhile, the pharmacological effects of bioactive components in jujube-based products were concluded. Jujube and its processed products contain rich polysaccharides, vitamin C, and other functional nutrients, which are beneficial to humans. As the initial processing method for jujubes, vacuum freezing or microwave drying have become the most commonly used and efficient drying methods. Additionally, processed jujube products cannot be separated from the maximum retention of nutrients and innovation of flavor. Fermentation is the main deep-processing method with broad development potential. In the future, chemical components and toxicological evaluation need to be combined with research to bring consumers higher quality functional jujube products and ensure the sustainable development of the jujube industry.

Bioavailability and mechanisms of dietary polyphenols affected by non-thermal processing technology in fruits and vegetables

Plant polyphenols play an essential role in human health. The bioactivity of polyphenols depends not only on their content but also on their bioavailability in food. The processing techniques, especially non-thermal processing, improve the retention and bioavailability of polyphenolic substances. However, there are limited studies summarizing the relationship between non-thermal processing, the bioavailability of polyphenols, and potential mechanisms. This review aims to summarize the effects of non-thermal processing techniques on the content and bioavailability of polyphenols in fruits and vegetables. Importantly, the disruption of cell walls and membranes, the inhibition of enzyme activities, free radical reactions, plant stress responses, and interactions of polyphenols with the food matrix caused by non-thermal processing are described. This study aims to enhance understanding of the significance of non-thermal processing technology in preserving the nutritional properties of dietary polyphenols in plant-based foods. It also offers theoretical support for the contribution of non-thermal processing technology in improving food nutrition.

Comprehensive evaluation of the effect of five sterilization methods on the quality of black carrot juice based on PCA, TOPSIS and GRA models

The effect of thermal pasteurization (TP), high temperature long time (HTLT), ultra-high temperature instantaneous (UHT), high hydrostatic pressure (HHP) and thermosonication (TS) sterilization on the physicochemical, sensory and functional properties of black carrot juice (BCJ) were studied. And for the first time, the comprehensive quality of sterilized BCJ was quantified by mathematical modeling. UHT was the least suitable sterilization method for BCJ resulting from the most severe deterioration in functional properties. TS had adverse effects on sensory and physicochemical properties, but significantly increased the total flavonoids and anthocyanins contents (p < 0.05) and showed the strongest antioxidant activity, making it a nutritional high-value processing method. TP and HHP balanced the improvement of sensory properties and the retention of functional properties, which were the most suitable sterilization methods for BCJ. This study determined the optimal sterilization methods of BCJ, and provided a scientific solution for the screening of high quality processing methods.

Investigation on the effect of thermal sterilization versus non-thermal sterilization on the quality parameters of jujube juice fermented by Lactobacillus plantarum

This study aimed to evaluate the jujube juice treated by four different sterilization treatments as substrates for producing a probiotic beverage fermented by Lactobacillus plantarum (L. plantarum): sterilization by autoclaving (SA at 0.1 MPa,121 °C, and 20 min), pasteurization (PS at 85 °C/30 min), cold plasma sterilization (CPS at 700 W/120 s) and pulsed strong light sterilization (PLS at 1.0 Hz, 600 J, and 10 times), while jujube juice without sterilization treatment used as control (CK). The results showed that the growth ability of L. plantarum in jujube juice was not affected by different sterilization treatments. After SA and PS treatment, the particle size of jujube juice increased by 440.51% and 222.29%, respectively, and the reducing sugar content decreased by 33.83% and 24.51%, respectively. Compared with SA and PS, PLS and CPS were beneficial to improve the stability of jujube juice, and tartaric acid content in jujube juice was significantly increased after CPS treatment. There was no significant difference in sensory and nutritional quality between PLS treated jujube juice and control, and the color of PLS treated jujube juice was significantly better than that of the other three sterilization treatments. The research indicated that PLS treatment could be a prospective sterilization method applied in the processing of fermented jujube juice.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05358-8.

Effect of High-Pressure Treatment on the Quality of a Hericium erinaceus: Millet Composite Beverage

Hericiumerinaceus-millet (HM) composite beverage was prepared by mixing Hericium erinaceus juice and millet juice and then subjected to high-pressure processing (HPP) of 300 MPa and 600 MPa at room temperature and thermal processing (TP) of 100°C for 3 min. The differences in pH, total soluble solids, amino acid nitrogen content, total colony numbers, sensory scores, and shelf life of HPP-treated and TP-treated samples stored at 4°C, 27°C, and 37°C for 80 days and the differences in volatile substances stored at 4°C and 27°C for 30 days were studied. The results showed that there was no significant difference in total soluble solids, amino acid nitrogen, and pH when comparing HPP- and TP-treated HM beverages. The order of HM beverages’ shelf life following different treatments was as follows: TP-treated >600 MPa HPP-treated >300 MPa HPP-treated. When stored at 4°C, the shelf life of the three treatments was 63, 52, and 39 days, respectively. Compared with TP-treated beverages, HPP-treated beverages better retained their ester flavor compounds, especially ethyl acetate. Moreover, the main volatile compounds in TP-treated beverages changed more during storage than those in HPP-treated beverages. Overall, HPP-treated beverages had advantages in terms of flavor over TP-treated beverages.

Impact of High-Pressure Processing on Antioxidant Activity during Storage of Fruits and Fruit Products: A Review

Fruits and fruit products are an essential part of the human diet. Their health benefits are directly related to their content of valuable bioactive compounds, such as polyphenols, anthocyanins, or vitamins. Heat treatments allow the production of stable and safe products; however, their sensory quality and chemical composition are subject to significant negative changes. The use of emerging non-thermal technologies, such as HPP (High Pressure Processing), has the potential to inactivate the microbial load while exerting minimal effects on the nutritional and organoleptic properties of food products. HPP is an adequate alternative to heat treatments and simultaneously achieves the purposes of preservation and maintenance of freshness characteristics and health benefits of the final products. However, compounds responsible for antioxidant activity can be significantly affected during treatment and storage of HPP-processed products. Therefore, this article reviews the effect of HPP treatment and subsequent storage on the antioxidant activity (oxygen radical absorbance capacity (ORAC) assay), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, ferric reducing antioxidant power (FRAP) assay, 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacity assay or Trolox equivalent antioxidant capacity (TEAC) assay), and on the total phenolic, flavonoid, carotenoid, anthocyanin and vitamin contents of fruits and different processed fruit-based products.