Ultrasonication of Thawed Huyou Juice: Effects on Cloud Stability, Physicochemical Properties and Bioactive Compounds

Citrus aurantium 'Changshan-huyou' physiological premature fruit drop: A promising prebiotic to tackle obesity

BACKGROUND

Presently, the mitigation and governance of obesity have surfaced as significant public health dilemmas on a global scale. A wealth of studies indicated that the host gut microbiota is instrumental in regulating the interplay between high-fat diet (HFD) intake and the pathogenesis of obesity. Physiological premature fruit drop, a major byproduct of citrus, is rich in a variety of bioactive constituents, yet its potential has remained underutilized for an extended period.

PURPOSE

The objective of this investigation is to examine the chemical constituents of Citrus aurantium'Changshan-huyou' premature fruit drop (HYFD) and investigate its anti-obesity effects, elucidating its potential pathways.

METHODS

Volatile compounds and flavonoids in HYFD were analyzed using chromatographic and mass spectrometric techniques. Furthermore, this study utilized biochemical assays and histopathological examinations to evaluate the effects of HYFD on HFD-fed mice. The impact of HYFD on the gut microbiota of the mice was examined through 16S rRNA gene sequencing, and fecal microbiota transplantation was employed to validate the role of the gut microbial community in host obesity prevention. Concurrently, transcriptome was employed to identify differentially expressed genes, providing further insights into the molecular mechanisms through which HYFD manifests its anti-obesity effects.

RESULTS

Our findings demonstrated that HYFD supplementation significantly alleviated adiposity and ameliorated the dysbiosis of gut microbiota in HFD-induced mice. HYFD rectified the HFD-induced gut microbiota dysregulation, enhanced the presence of beneficial microbial taxa linked to lipid metabolism, including Parabacteroides and Alistipes, and elevated concentrations of the anti-obesity short-chain fatty acids, comprising caproic acid and isocaproic acid. Additionally, transcriptomic analyses confirmed that HYFD prevented obesity in mice by enhancing fatty acid catabolism via the activation of the AMPK/PPARα/CPT1a signaling pathway.

CONCLUSION

Our results provided novel insights into the mechanism of citrus physiological premature fruit drop and its potential role in preventing obesity, while sparking greater interest in leveraging more biomass waste.

Variations in volatile components and biological activities of essential oils from Citrus aurantium 'changshanhuyou' at different growth and ripening stages

Citrus aurantium 'Changshanhuyou' is one kind of fruit that is beneficial to human health. Most research focus on active substances such as flavonoids and limonoids, but few on the essential oils from its peels. This study analyzed the volatile components of Huyou peel essential oil (HYEO) throughout the growth and ripening stages including beginning, middle, end of growth period, and post- ripening stage (60 days of storage) by GC-MS. The results identified approximately 70 components in HYEO, and the level of oxygenated monoterpenes decreased while sesquiterpenes increased with the ripening of the huyou. The essential oil after 60 days of storage showed outstanding antioxidant properties (DPPH, IC50 = 101.77 ± 0.83 mg/mL; ABTS, IC50 = 18.11 ± 0.74 mg/mL), antibacterial (zones of inhibition: E. coli, 28.18 ± 1.37 mm; S. aureus, 20.40 ± 0.84 mm; S. Typhimurium, 27.17 ± 1.14 mm; L. monocytogenes, 22.83 ± 1.27 mm) and antidiabetic (IC50 = 5.26 ± 0.58 mg/mL) activities due to high levels of p-cymenene, cis-carveol, and D-carvone detected. Results from the corticosterone-damaged mouse neuronal cell model, the essential oil extracted from the middle of the growth period demonstrates the best antidepressant activity due to high content of citronellol, elemene, linalool, and citronel detected. Overall, this study provides a valuable reference for exploiting and evaluating essential oils from Huyou peels with multifunctions in food and medicine industry.

Effects of Ultrasonic Treatment on Physical Stability of Lily Juice: Rheological Behavior, Particle Size, and Microstructure

The aim of this study was to investigate the rheological properties, particle size distribution, color change, and stability of lily juice under different ultrasonic treatment conditions (152 W, 304 W, 456 W, 608 W, and 760 W). The results showed that the lily juice exhibited non-Newtonian shear thinning behavior, and the viscosity decreased with the increase in ultrasonic power. Under ultrasonic treatment conditions, there was no significant change in the pH value and zeta potential value of the samples. The content of cloudy value and total soluble solids (TSS) increased gradually. However, both the sedimentation components and centrifugal sedimentation rate showed a downward trend and an asymptotic behavior. In addition, high-power ultrasound changed the color index (L* value decreased, a* value increased), tissue structure, and particle distribution of the sample, and small particles increased significantly. To sum up, ultrasonic treatment has great potential in improving the physical properties and suspension stability of lily juice.

Citrus aurantium ‘Changshan-huyou’—An ethnopharmacological and phytochemical review

Citrus fruits are composed of oil cells layer, white membrane layer, pulp and seeds. The cultivar Citrus aurantium ‘Changshan-huyou’ (CACH) is a hybridization of Citrus grandis Osbeck and C. sinensis Osbeck. It is a rutaceae plant, and mainly grows in Changshan, Zhejiang, China. With the exploration of its high traditional values, it has been paid more and more attention by the scientific community in recent years. At present, one hundred and two chemical constituents have been identified from the pulp and peel of CACH, including volatile oils, terpenoids, phenols, limonins, sugars, etc., As the representative active component of CACH, phenols have been widely investigated. Studies have shown that CACH shows a variety of significant pharmacological activities, such as anti-inflammatory, antioxidant, hepatoprotective activity, respiratory system protection and intestinal regulation activity. This review mainly introduces the chemical constituents and pharmacological activities of CACH, and discusses its future research and development directions. It will provide theoretical basis for further research of its pharmacodynamic substances, functional mechanism and rational utilization.

Effect of Multi-Mode Thermosonication on the Microbial Inhibition and Quality Retention of Strawberry Clear Juice during Storage at Varied Temperatures

Strawberry juice, which is rich in nutrients and charming flavor, is favored by consumers. To explore whether multi-mode thermosonication (MTS) can ensure the quality stability of strawberry clear juice (SCJ) during storage, the effects of microbial inhibition, enzyme activity, and physicochemical properties of SCJ pretreated by MTS were evaluated during storage at 4, 25, and 37 °C in comparison with thermal pretreatment (TP) at 90 °C for 1 min. The MTS, including dual-frequency energy-gathered ultrasound pretreatment (DEUP) and flat sweep-frequency dispersive ultrasound pretreatment (FSDUP), were conducted at 60 °C for 5 and 15 min, respectively. Results showed that the total phenols, flavonoids, anthocyanins, ascorbic acid, and DPPH free radical scavenging ability of SCJ decreased during the storage period. The control sample of SCJ was able to sage for only 7 days at 4 °C based on the microbiological quality, while the FSDUP and DEUP group extended the storage period up to 21 and 14 days, respectively. The polyphenol oxidase in SCJ pretreated by MTS did not reactivate during the storage period. The MTS remarkably (p < 0.05) reduced the color deterioration, browning degree, and nutrient degradation during the storage period. Moreover, the FSDUP group exhibited the maximum shelf life with a minimum loss of quality, demonstrating that it was the most suitable processing method for obtaining high-quality SCJ. It can be concluded that the MTS has the potential to inhibit enzymatic browning, inactivating microorganisms, preserve original quality attributes, and prolong the shelf life of SCJ.

Effects of Fruit Storage Temperature and Time on Cloud Stability of Not from Concentrated Apple Juice

Apple juice that is designated ‘Not from concentrated’ (NFC) is now increasingly popular with consumers due to its unique taste and rich nutritional value. However, layered precipitation and instability have emerged as serious technical problems that restrict the viability of the NFC apple juice industry. This study researched the influence of water-cored ‘Fuji’ apple fruit storage under different temperatures (0, 20 °C) and times (0, 9, 18, 30, 60 days) on the turbidity stability of NFC apple juice. Changes in the physicochemical properties (juice yield, pH, total soluble solids and titratable acid), turbidity stability (turbidity and particle size) and precipitation sensitive substances (insoluble starch, total phenolics, soluble protein and pectin) of NFC apple juice were determined, combined with the respiratory rates and ethylene release of apples, in order to study post-harvest regulation and control of processed fruit. Results indicated that fruit storage temperature and time significantly guided the turbidity stability of NFC apple juice. As a typical respiratory climacteric fruit, apple fruit stored 45 days at 0 °C and 15 days at 20 °C gained the best juice stability, respectively. This is basically consistent with the respiratory peak of fruit when processing raw materials. During the post-ripening process, the insoluble starch in apple gradually hydrolyzed into fructose and glucose, while total phenolics diminished and water-soluble pectin content increased. On the other hand, the amounts of pectin, soluble protein and phenolics in fruit juice declined as the fruit aged in the late storage period (stored 75 days at 0 °C and 40 days at 20 °C). Meanwhile particle size became larger and the turbidity stability of cloudy juices also decreased. This study’s results will provide a sound theoretical basis for improving the turbidity stability of NFC apple juice by regulating the physiological state of processed raw materials.