Extraction, Physicochemical Properties, and In Vitro Antioxidant Activities of Chondroitin Sulfate from Bovine Nose Cartilage.

Beef is an important high-nutrition livestock product, and several byproducts, such as bovine cartilage, are produced during slaughter. To effectively utilize these agricultural and pastoral byproducts, combined (trypsin-papain) enzymolysis and cetylpyridine chloride purification methods were used to obtain chondroitin sulfate (CS) from the nasal cartilage of Shaanxi Yellow cattle. The effects of pH, temperature, and time on the CS yield during enzymatic hydrolysis were investigated, and the CS extraction process was optimized using response surface methodology. The best yield of CS was 21.62% under the optimum conditions of pH 6.51, temperature of 64.53°C, and enzymolysis time of 19.86 h. The molecular weight of CS from Shaanxi cattle nasal cartilage was 89.21 kDa, glucuronic acid content was 31.76 ± 0.72%, protein content was 1.12 ± 0.03%, and sulfate group content was 23.34 ± 0.08%. The nasal cartilage CS of the Yellow cattle showed strong DPPH•, •OH, and ABTS+• radical scavenging abilities and ferrous reduction ability in the experimental concentration range. This study could contribute to "turn waste into treasure" and improve the comprehensive utilization of regional characteristic biological resources.

Effects of konjac glucomannan/pomegranate peel extract composite coating on the quality and nutritional properties of fresh-cut kiwifruit and green bell pepper.

The effects of an edible coating, based on konjac glucomannan (KG) incorporated with pomegranate peel extracts (PE), on the physicochemical and nutritional properties of fresh-cut kiwifruit and green bell pepper during storage were investigated. The optimal extract time (40.6 min), temperature (54.5 °C), and ultrasound power (255.5 W) with response surface method, provided a high total antioxidant activity (TAA) of (92.31 ± 1.43)%. Fresh-cut kiwifruit and green bell pepper were coated by dipping using five treatments (distilled water, ascorbic acid, KG, PE, KG + PE), packed into polymeric film and stored for 8 days at 10 °C. Distilled water treatment was used as control. KG + PE treatment resulted in the highest total soluble solid and titratable acidity in fresh-cut kiwifruit, while the maximum firmness in fresh-cut green bell pepper. The weight loss was both effectively decreased in samples treated with KG or KG + PE. All samples treated with KG + PE had significantly higher contents of chlorophyll, ascorbic acid, total phenolic and TAA than others. Moreover, the KG + PE group had the lowest counts of microorganisms in all samples. KG coating incorporated with PE was proved to be efficient in maintaining the physico-chemical and nutritional properties of fresh-cut kiwifruit and green bell pepper during low temperature storage compared with control. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-021-05006-7.

Sulforaphane and its antioxidative effects in broccoli seeds and sprouts of different cultivars.

The purpose of this study was to clearly understand the health-promoting potentials of broccoli seeds and sprouts according to identify their representative bioactive compounds and antioxidant activities in six varieties. Sulforaphane (SF) extraction was firstly optimized from seeds and sprouts. Then SF extracted under optimized conditions from seeds and sprouts were compared. Most varieties obtained the maximum SF, total phenolic (TP) and flavonoid (TF) contents in sprouts on day 3. SF contents in sprouts were 46%-97% of seeds, whereas TP and TF contents in sprouts were 1.12-3.58 times higher than seeds among varieties. After in vitro digestion, broccoli sprouts from MNL variety kept considerable SF, TF, and TP contents, as well as antioxidant capacities, with all values higher than seeds. Compared with seeds, sprouts after 3 days germination were also recommended as raw materials of functional foods that possess high health-promoting potential.