Evaluation of Loquat Jam Quality at Different Cooking Times Based on Physicochemical Parameters, GC-IMS and Intelligent Senses.

The study compared and analyzed the quality of loquat jam with different cooking times through physicochemical parameters, headspace-gas chromatography-ion migration spectroscopy (HS-GC-IMS) and intelligent senses. The results showed that with the prolongation of the cooking time, the color of loquat jam slowly deepened, the energy significantly increased, the adhesiveness, gumminess, hardness and chewiness enhanced, the free amino acid content increased from 22.40 to 65.18 mg/g. The organic acid content increased from 1.64 to 9.82 mg/g. Forty-seven volatile flavor compounds were identified in five types of loquat jam using HS-GC-IMS, among which the relative content of aldehydes was sharply higher than that of other chemical substances, playing an important role in the flavor formation of loquat jam. LJ0, LJ1 and LJ2 had higher aldehyde content, followed by LJ3 and LJ4 had the lowest aldehyde content. The orthogonal partial least squares-discriminant analysis (OPLS-DA) screened 15 marker compounds that could distinguish five types of loquat jam. The E-nose results showed a significant difference in olfactory sense between loquat jam cooked for 100 and 120 min. The E-tongue results corroborated the results of free amino acids (FAAs) and organic acids, indicating that the gustatory sense of loquat jam changed significantly when the cooking time reached 120 min. The results provided a basis for further research on the relationship between the cooking process and quality characteristics of loquat jam.

Recent Advances in Bioactive Compounds, Health Functions, and Safety Concerns of Onion (Allium cepa L.).

Onion (Allium cepa L.) is a common vegetable, widely consumed all over the world. Onion contains diverse phytochemicals, including organosulfur compounds, phenolic compounds, polysaccharides, and saponins. The phenolic and sulfur-containing compounds, including onionin A, cysteine sulfoxides, quercetin, and quercetin glucosides, are the major bioactive constituents of onion. Accumulated studies have revealed that onion and its bioactive compounds possess various health functions, such as antioxidant, antimicrobial, anti-inflammatory, anti-obesity, anti-diabetic, anticancer, cardiovascular protective, neuroprotective, hepatorenal protective, respiratory protective, digestive system protective, reproductive protective, and immunomodulatory properties. Herein, the main bioactive compounds in onion are summarized, followed by intensively discussing its major health functions as well as relevant molecular mechanisms. Moreover, the potential safety concerns about onion contamination and the ways to mitigate these issues are also discussed. We hope that this paper can attract broader attention to onion and its bioactive compounds, which are promising ingredients in the development of functional foods and nutraceuticals for preventing and managing certain chronic diseases.

The ameliorative effect of silicon on soybean seedlings grown in potassium-deficient medium.

BACKGROUND AND AIMS: Crop yield and nutritional quality are significantly reduced when potassium (K) in soil is deficient. As a beneficial element for plants, silicon (Si) is effective in alleviating the toxic effects of mineral nutrients. However, the roles played by Si in mediating deficiency in essential mineral nutrients in general and K in particular have not been investigated. METHODS: To evaluate the role of Si in K deficiency-induced inhibition of growth of soybean (Glycine max) seedlings, the effects of K deficiency on shoot and root growth, hydrogen peroxide accumulation, K contents, lipid peroxidation and activities of antioxidant enzymes in the absence and presence of 2 mM sodium silicate (Na(2)SiO(3)) were investigated. KEY RESULTS: Both shoot and root biomass of soybean seedlings were markedly reduced when grown in K-deficient medium (1 mM K) compared with those grown in K-sufficient medium (5 mM). Addition of Na(2)SiO(3) significantly ameliorated the K deficiency-induced reductions in shoot and root growth. Sodium silicate enhanced K concentrations in leaf, stem and root of K-deficient seedlings by 105.4, 83.4 and 58.8 %, respectively. Hydrogen peroxide (H(2)O(2)) and malondialdehyde (MDA) contents in soybean seedlings were increased by 25 and 97 %, respectively, when exposed to K-deficient medium. These increases in accumulation of H(2)O(2) and MDA were removed by addition of Na(2)SiO(3). Addition of Na(2)SiO(3) reduced the K deficiency-induced increases in activities of superoxide dismutase, catalase and peroxidase. CONCLUSIONS: Application of Si to soybean seedlings grown in K-deficient medium markedly enhanced K use efficiency. Therefore, Si not only increases tolerance to nutrient toxicity, but also ameliorates symptoms associated with deficiency in essential nutrients in plants.