Evaluation of Different Black Mulberry Fruits (Morus nigra L.) Based on Phenolic Compounds and Antioxidant Activity.

This study evaluated thirteen different black mulberry fruits (Morus nigra L.) grown in the Guangdong region in order to select the best cultivar for health benefits and commercial applications. The phenolic compounds were identified and quantified using UPLC-ESI-MS/MS. The antioxidant activity was evaluated by three in vitro methods. Significant differences among samples were found regarding total soluble solids (6.20-15.83 °Brix), titratable acidity (5.82-48.49 mg CA/g), total phenolic contents (10.82-27.29 mg GAE/g), total flavonoid contents (1.21-2.86 mg RE/g) and total anthocyanin contents (2.91-11.86 mg CE/g). Fifty-five different phenolic compounds were identified, of which fifteen were reported in mulberry for the first time, but only forty-six of them were quantitated. The DPPH radical scavenging activity, ABTS radical scavenging activity and ferric ion-reducing antioxidant power varied significantly among the samples. Overall, cultivars with better combinations of phenolic compounds and antioxidant activity were Qiong46 (M-2), Yuebanguo (M-4) and Heizhenzhu (M-10), which were recommended for commercial cultivation.

Pectin/Activated Carbon-Based Porous Microsphere for Pb2+ Adsorption: Characterization and Adsorption Behaviour.

The development of effective heavy metal adsorbents has always been the goal of environmentalists. Pectin/activated carbon microspheres (P/ACs) were prepared through simple gelation without chemical crosslinking and utilized for adsorption of Pb2+. Scanning electron microscopy (SEM) revealed that the addition of activated carbon increased the porosity of the microsphere. Texture profile analysis showed good mechanical strength of P/ACs compared with original pectin microspheres. Kinetic studies found that the adsorption process followed a pseudo-second-order model, and the adsorption rate was controlled by film diffusion. Adsorption isotherms were described well by a Langmuir isotherm model, and the maximum adsorption capacity was estimated to be 279.33 mg/g. The P/ACs with the highest activated carbon (P/AC2:3) maintained a removal rate over 95.5% after 10 adsorption/desorption cycles. SEM-energy-dispersive X-ray spectrum and XPS analysis suggested a potential mechanism of adsorption are ion exchange between Pb2+ and Ca2+, electronic adsorption, formation of complexes, and physical adsorption of P/ACs. All the above results indicated the P/ACs may be a good candidate for the adsorption of Pb2+.

Solubility Difference between Pectic Fractions from Creeping Fig Seeds.

Crude water-extracted pectin (WEP) isolated from creeping fig seeds were mainly fractionated into WEP-0.3 and WEP-0.4 fractions. Fractions were confirmed to be nonstarch, nonreducing sugars, nonpolyphenols and protein-unbounded acidic polysaccharides. Interestingly, a significant difference in solubility was found between WEP-0.3 (higher solubility than WEP) and WEP-0.4 (remarkably insoluble), which was consistent with the amorphous and porous sponge-like structure of WEP-0.3 as well as the crystalline and dense rod-like state of WEP-0.4. However, the result of the FT-IR spectra was contradicted by the solubility of WEP-0.4, which possessed the lowest degree of methoxylation and ought to possess the highest solubility. Through mineral analysis, a considerably high content of Ca2+ was found in WEP-0.4, suggesting that the low solubility of WEP-0.4 was probably attributable to the formation of microgels during dialysis. Therefore, metal divalent cations in the dialysate were suggested to be depleted for the dialysis of low methoxyl pectin.

Dynamic high-pressure microfluidization assisting octenyl succinic anhydride modification of rice starch.

Octenyl succinic anhydride (OSA) modified starch is widely used in food industries. In this study, rice starch (RS) was pretreated by dynamic high-pressure microfluidization (DHPM) and subsequently modified by OSA. The influence of DHPM on OSA modification of rice starch was investigated. Results showed that DHPM pretreatment enhanced the degree of substitution by changing the morphology and crystallinity of rice starch. Compared with the rice starch modified by OSA without DHPM pretreatment (OSA-RS), the DHPM-pretreated OSA starch (DHPM-OSA-RS) presented higher peak viscosity and lower pasting temperature. DHPM-OSA-RS also exhibited better emulsifying activity and emulsion stability. This study suggested that DHPM will provide an opportunity to change the physicochemical properties of starch, with the resulting starch being more suitable for chemical modification.