ABSTRACT
Objective Using different sterilization method to sterilize pig specific formula milk powder,exploring the sterilization method and conditions that minimize the loss of nutritional components in formula milk powder.Methods Pig-specific formula milk powder was divided into high-pressure sterilization and irradiation sterilization groups.Formula milk powder in the high-pressure group was sterilized using different sterilization conditions and that in the irradiation group was sterilized using different 60 Co γ-radiation doses.The sterility and the nutritional contents of the sterilized formula milk powders were determined according to national standards.Results The sterility tests for both groups of formula milk powder were negative.Compared to control group,the crude protein contents were significantly lower in formula in the high-pressure group sterilized at 121℃for 30 min and in the irradiation liquid group sterilized at 50 kGy(P<0.01).The water,crude protein,and calcium contents were significantly lower(P<0.001)in the irradiation group sterilized at 50 kGy.There was no significant difference in the valine,isoleucine,or leucine content under 50 kGy sterilization conditions in the irradiation sterilized group,but all amino acid contents were decreased in the high-pressure sterilization and irradiation sterilized liquid groups(P<0.001).Analysis of trace elements showed an increased iron content(P<0.001)in formula sterilized at 121℃for 30 min in the high-pressure sterilization group,increased iron and potassium contents(P<0.001)under 25 kGy sterilization conditions in the irradiation sterilization liquid group,and increased magnesium content(P<0.01).The magnesium(P<0.05)and sodium contents(P<0.01)differed significantly in formula treated under 50 kGy sterilization conditions in the irradiation sterilized powder group.VE and VB2 contents were increased in formula sterilized at 121℃for 30 min in the high-pressure sterilization group(P<0.001),the VE content was increased(P<0.05)and the VB2 content was decreased(P<0.001)in formula sterilized under 50 kGy conditions in the irradiation sterilization liquid group,and the VE and VA contents were decreased in formula sterilized at 25 kGy in the irradiation sterilized powder group(P<0.001).Conclusions Sterilization at 121℃for 30 min result ed in the least loss of nutritional components in the high-pressure sterilization group,while irradiation sterilization result ed in the least loss of nutrients at a dose of 50 kGy.Comparing the two sterilization method,irradiation of milk powder at 50 kGy result ed in the least loss of nutrient content.
ABSTRACT
Objective To investigate the characteristics of gut microbiota in SD rat model of diabetes mellitus induced by streptozotocin (STZ). Methods Twenty-five male SD rats were randomly divided into control (C) (n＝10) and diabetes (M) (n＝15) groups. Rats in the group M received intravenous injection of streptozotocin (30 mg/kg) once per day for 5 consecutive days. Fecal samples were collected and examined for the V3 region of the 16S rDNA gene by Illumina Miseq high-throughput sequencing. The abundance and composition of gut microbiota were analyzed by cluster analysis. Results DNA sequence analysis was successfully performed. The Chao 1 index was lower in the group M than group C (P＜ 0. 05). The Shannon index was lower and the Simpson index was higher in the group M than group C (P＜0. 05). At phylum level, the relative abundance of Proteobacteria, Cyanobacteria, Tenericutes, TM7, and Actinobacteria was lower in the group M than group C (P＜ 0. 05). At genus level, 4 weeks after injection,the abundance of Lactobacillus was lower and that of Bacteroidetes was higher in the group M than group C ( P＜ 0. 05). 12 weeks after injection, the relative abundance of Lactobacillus,Bacteroides and Ruminococcus was higher and that of Bifidobacterium was lower in the group M than group C ( P＜ 0. 05). Conclusions This STZ-induced diabetic SD rat model has a low abundance and diversity of gut microbiota. Quantitative analysis of gut microbiota composition in this animal model provides a basic data for the study of relationship between diabetes mellitus and gut microbiota.