Effect of salt concentration on microbial communities, physicochemical properties and metabolite profile during spontaneous fermentation of Chinese northeast sauerkraut

AIM

The aim of this study was to study the effects of salt concentrations on the microbial communities, physicochemical properties, metabolome profiles and sensory characteristics during the fermentation of traditional northeast sauerkraut.

METHODS AND RESULTS

Northeast sauerkraut was spontaneously fermented under four salt concentrations (0·5, 1·5, 2·5 and 3·5%, w/w). The result of microbiological analysis showed that the population of lactic acid bacteria in 2·5%-salted sauerkraut was significantly higher than that in the other samples. Correspondingly, the speed of decrease in pH and accumulation of acids were the highest in 2·5%-salted sauerkraut. The glucose (analysed by HPLC) in 2·5%-salted sauerkraut was consumed more completely to produce higher levels of organic acids compared to those in the other samples. Principle component analysis showed clear differences in the metabolites of sauerkraut according to different salt concentrations. A higher level of volatiles (detected by HS-SPME/GC-MS) was identified in 2·5%-salted sauerkraut, and sensory evaluation demonstrated that 2·5%-salted sauerkraut had the best sensory characteristics.

CONCLUSION

The best quality of sauerkraut was obtained from fermented under 2·5% salt concentration.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study facilitated the understanding of the effects of salt on the sauerkraut fermentation and may be useful for developing the quality of sauerkraut.

Elevated Blood Pressure and Associations with Sodium Intake Among Multiethnic Youth in Edmonton, Canada: Findings from WHY ACT NOW

INTRODUCTION

This study examined the prevalence of pre-hypertension (PHT) and hypertension (HT) in urban youth, and assessed the effects of sodium intake and obesity on blood pressure (BP) by ethnicity.

METHODS

A convenience sample of 557 multiethnic youth, aged 11-23 years, was recruited from 12 schools and institutions in Edmonton, Alberta, Canada. Participants were divided by self-identified ethnicity into four groups (Indigenous, African and Middle Eastern (AME), Asian, and European).

RESULTS

Between October 2013 and March 2014, one-on-one interviews were conducted to collect data on demographics, physical activity, diet, and Body Mass Index (BMI). BP was obtained at two different times during the interview and measured a third time in cases of high variability. The standard deviation scores (SDS) of systolic BP (SBP) and diastolic BP (DBP) were used to estimate associations with sodium intake (per 1000 mg/day). Overall, 18.2% and 5.4% of the participants had PHT and HT, respectively. Indigenous and AME participants showed the highest rates of PHT (23.1%). Indigenous and European participants showed higher rates of HT (8.3% and 5.3%, respectively) than other ethnic groups (AME = 4.4%, Asian = 3.9%). There was a positive association between 1000 mg/day increase in sodium intake and SDS of SBP by 0.041 (95% CI 0.007-0.083; p = 0.04) among pre-hypertensive participants. Over 85% of participants exceeded the recommended dietary sodium intake. Mean BMI and dietary sodium intake were higher among pre-hypertensive participants (4219 mg/day) than normotensive (3475 mg/day).

CONCLUSIONS

The prevalence of HT varied by ethnicity. High dietary sodium intake was of concern. There is a need for culturally-tailored, population-based interventions to reduce sodium intake.