Effects of preheating and drying methods on pyridoxine, phenolic compounds, ginkgolic acids, and antioxidant capacity of Ginkgo biloba nuts

Flavor characteristics of peeled walnut kernels under two-steps roasting processes

Currently, the effects of roasting methods on the flavor profile of peeled walnut kernels (PWKs) remain unknown. The effects of hot air binding (HAHA), radio frequency (HARF), and microwave irradiation (HAMW) on PWK were evaluated using olfactory, sensory, and textural techniques. Solvent Assisted Flavor Evaporation-Gas Chromatography-Olfactometry (SAFE-GC-O) identified 21 odor-active compounds with total concentrations of 229 μg/kg, 273 μg/kg and 499 μg/kg due to HAHA, HARF, and HAMW, respectively. HAMW exhibited the most prominent nutty taste, with the highest response among roasted milky sensors with the typical aroma of 2-ethyl-5-methylpyrazine. HARF had the highest values for chewiness (5.83 N·mm) and brittleness (0.68 mm); however, these attributes did not contribute to the flavor profile. The partial least squares regression (PLSR) model and VIP values showed 13 odor-active compounds were responsible for the sensory differences from different processes. The two-step treatment with HAMW improved the flavor quality of PWK.

Site-Directed Mutation of Salicylate Decarboxylase Gene and Mechanism of Ginkgo Acid Decarboxylation

Ginkgo seed is an important Chinese medicine and food resource in China, but the toxicity of ginkgo acid in it limits its application. Previous studies have found that salicylic acid decarboxylase (Sdc) has a decarboxylation degradation effect on ginkgo acid. In order to improve the decarboxylation ability of Sdc to Ginkgo acid, 11 residues of the Sdc around the substrate (salicylic acid) were determined as mutation targets according to the analysis of crystal structure of Sdc (PDB ID:6JQX), from Trichosporon moniliiforme WU-0401, and a total of 30 single point mutant enzymes and one compound mutant enzyme were obtained. With Ginkgo acid C15:1 as the substrate, it was found from activity assay that Sdc-Y64T and Sdc-P191A had higher decarboxylation activity, which increased by 105.18% and 116.74% compared with that of wild type Sdc, respectively. The optimal pH for Sdc Y64T and Sdc-P191A to decarboxylate Ginkgo acid C15:1 was 5.5, which is the same as the wild type Sdc. The optimal temperature of Sdc-P191A was 50 °C, which was consistent with that of the wild type Sdc, but the optimal temperature of the mutant Sdc-Y64T was 40 °C, which was 10 °C lower than that of wild type Sdc.

Quercetin Impact in Pancreatic Cancer: An Overview on Its Therapeutic Effects

Pancreatic cancer (PC) is a lethal malignancy cancer, and its mortality rates have been increasing worldwide. Diagnosis of this cancer is complicated, as it does not often present symptoms, and most patients present an irremediable tumor having a 5-year survival rate after diagnosis. Regarding treatment, many concerns have also been raised, as most tumors are found at advanced stages. At present, anticancer compounds-rich foods have been utilized to control PC. Among such bioactive molecules, flavonoid compounds have shown excellent anticancer abilities, such as quercetin, which has been used as an adjunctive or alternative drug to PC treatment by inhibitory or stimulatory biological mechanisms including autophagy, apoptosis, cell growth reduction or inhibition, EMT, oxidative stress, and enhancing sensitivity to chemotherapy agents. The recognition that this natural product has beneficial effects on cancer treatment has boosted the researchers' interest towards more extensive studies to use herbal medicine for anticancer purposes. In addition, due to the expensive cost and high rate of side effects of anticancer drugs, attempts have been made to use quercetin but also other flavonoids for preventing and treating PC. Based on related studies, it has been found that the quercetin compound has significant effect on cancerous cell lines as well as animal models. Therefore, it can be used as a supplementary drug to treat a variety of cancers, particularly pancreatic cancer. This review is aimed at discussing the therapeutic effects of quercetin by targeting the molecular signaling pathway and identifying antigrowth, cell proliferation, antioxidative stress, EMT, induction of apoptotic, and autophagic features.