Considerable controversy exists regarding the association between dietary calcium intake and risk of mortality from cardiovascular disease and all causes. Therefore, we performed a meta-analysis of prospective cohort studies to examine the controversy. We identified relevant studies by searching MEDLINE, Embase, and the Cochrane Library databases between 1 September 2013 and 30 December 2013. Reference lists of relevant articles were also reviewed. Observational prospective studies that reported relative risks and 95% confidence intervals for the association of calcium intake with cardiovascular and all-cause mortality were eligible. Study-specific relative risks were pooled using a random-effects model. In this meta-analysis, 11 prospective studies with 12 independent cohorts, involving 757,304 participants, were eligible. There was evidence of a non-linear association between dietary calcium intake and risk of mortality from cardiovascular disease (P for non-linearity <0.01) and all causes (P for non-linearity 900 mg/day) is not associated with a decreased risk of all-cause mortality.

Oxidative stress is a major risk factor in the onset and progression of type 2 diabetes mellitus (T2DM). NF-E2 related factor 2 (NRF2) is a pivotal transcription factor in oxidative stress related illnesses. This study included 2174 subjects with 879 cases of newly-diagnosed T2DM and 1295 healthy controls. Compared to individuals with the CC genotype, those with the AA genotype had lower total anti-oxidative capacity, superoxide dismutase, catalase, glutathione, glutathione peroxidase activity; and lower homeostasis model assessment of β-cell function index. Those with the AA genotype also had a higher malondialdehyde concentration and homeostasis model assessment of insulin resistance index values. The frequency of allele A was significantly higher in T2DM subjects (29.4%), compared to control subjects (26.1%; p = 0.019). Individuals with the AA genotype had a significantly higher risk of developing T2DM (OR 1.56; 95% CI 1.11, 2.20; p = 0.011), relative to those with the CC genotype, even after adjusting for known T2DM risk factors. Our results suggest that the NRF2 rs6721961 polymorphism was significantly associated with oxidative stress, anti-oxidative status, and risk of newly-diagnosed T2DM. This polymorphism may also contribute to impaired insulin secretory capacity and increased insulin resistance in a Chinese population.

Fermentation technology has a long history and low-temperature fermentation has now become the focus of research. This paper reviews the mechanism and application of low-temperature fermentation and the optimization of relevant strains. Low-temperature fermentation leads to a differential expression of growth in metabolism genes (PSD1, OPI3, ERG3, LCB3 and NTH1). Low-temperature fermentation can be applied to foods and has various advantages, such as increasing changes in volatile flavor compounds and other corresponding metabolic substances of the strain, and inhibited growth of spurious bacteria. The focus of low-temperature fermentation in the long run lies in strain optimization, which is to protect and optimize the strains through a variety of methods. Low-temperature fermentation can greatly improve product quality. At present, the most effective methods to promote low-temperature fermentation are gene knockout and probiotic microencapsulation.

With a prolonged refrigeration time, dough becomes syruped and the gluten strength is weakened, which negatively affects the texture of the dough. At the same time, differences in the growth and metabolism of different yeasts lead to large differences in the physicochemical properties of the dough and the final quality of the product. Therefore, in this study, suitable additives and non-Saccharomyces cerevisiae were selected to minimize the effects of long-term refrigeration on the physicochemical properties and microstructure of fermented doughs. Compared to the control group without mixed yeast strains and additives, the fermentation properties, textural properties, dynamic rheology, starch crystallinity, protein structure, water distribution, and microstructure were investigated by mixed yeast strains and additives for 14 days of long-term refrigeration. The results showed that using mixed yeast strains (Saccharomyces cerevisiae: Metschnikowia pulcherrima; Wickerhamomyces anomalous = 0.46:0.27:0.27), α-amylase, diacetyl tartaric acid ester of mono(di)glycerides and polydextrose can avoid the excessive fermentation of refrigerated dough. In addition, mixed yeast strains and additives could maintain the orderliness of the secondary structure of gluten proteins, stabilize the microstructure of starch and gluten proteins, and reduce the migration and loss of water in the dough. This study clarified that mixed yeast strains and additives are conducive to prolonging the long-term refrigeration of dough, and could better maintain the quality of dough during long-term refrigeration. These results provide a theoretical basis for further research on the large-scale production of refrigerated fermented dough.