Table of Content

01 May 2017, Volume 40 Issue 3

Previous Issue    Next Issue

Processing Technology

Formulation Optimization of a Goat Milk-Based Product with Lactation-Promoting Effects and Health Benefits by Response Surface Methodology

LI Jing, WANG Cunfang

2017, 40(3):  1-6.  DOI: 10.15922/j.cnki.jdst.2017.03.001

Asbtract ( )   PDF (2243KB) ( )  

Related Articles | Metrics

A goat milk-based product with lactation-promoting effects and health benefits was formulated with goat milk, millet flour, gelatin, fig and medicinal plant extract. Optimization of the formulation was done using one-factor-at-a-time and orthogonal array design methods. The responses were sensory evaluation scores and hardness. The optimum formulation was found to consist of the addition of 31% millet flour, 1.01% gelatin, 13.17% fig, and 10% medicinal plant extract to fresh goat milk. The formulated product had a smooth surface, a delicate sweet flavor, a strong milk taste and an even color, and its sensory score and hardness were 96.30 and 366.53 g, respectively. The nutritional and health-promoting components of the raw materials were maximally retained in the product.

Analysis & Detection

Ultrasonic-Assisted Extraction of Lipids for the Determination of the Peroxide Value of Infant Formulas

JIA Hongxin, JIANG Wenyao, SU Miya

2017, 40(3):  7-10.  DOI: 10.15922/j.cnki.jdst.2017.03.002

Asbtract ( )   PDF (1584KB) ( )  

Related Articles | Metrics

An ultrasonic-assisted extraction procedure was developed for the determination of the peroxide value (POV) in infant formulas. The extraction parameters such as extractant type, amount of sample, number of extraction cycles and ultrasonic conditions were optimized. The proposed method gave high extraction yield (> 95%) and allowed accurate determination of POV. Under accelerated oxidation conditions, the shelf-life of infant formulas could be accurately reflected by POV values determined this method.

Simultaneous Determination of Chloropropanol Esters in Infant Formula Milk Powder by Isotope Internal Standard Coupled with Gas Chromatography-Mass Spectrometry

LIU Yuan, LU Jian

2017, 40(3):  11-15.  DOI: 10.15922/j.cnki.jdst.2017.03.003

Asbtract ( )   PDF (1544KB) ( )  

Related Articles | Metrics

An isotope internal standard coupled with gas chromatography-mass spectrometry (GC-MS) method was established for the simultaneous determination of four chloropropanol esters (3-chloro-1,2-propanediol, 2-chloro-1,3-propanediol, 1,3-dichloro-2-propanediol and 2,3-dichloro-2-propanol ester) in infant formula milk powder. Samples were dissolved and extracted withn-hexane, and then the extract was hydrolyzed by sodium methoxide in methanol, purified on a Florisil solid phase extraction column, derivatized with heptafluorobutyryl imidazole, detected by GC-MS in the single ion monitoring mode, and quantified by the internal standard method. Under the optimized conditions, all four chloropropanol esters showed good linearity in the range of 0.05–1.00 mg/L withR2 larger than 0.997. The detection limit of the method was 0.015 mg/kg. The mean recoveries at three spiked concentration levels (0.05, 0.10 and 0.50 mg/kg) were in the range of 85.9%–102.1% with relative standard deviations (RSDs,n = 6) ranging from 2.4% to 5.6%. The proposed method showed the advantages of high sensitivity, good clean-up efficiency and high accuracy, and it was suitable for the detection of chloropropanol esters in infant formula milk powder.

Determination of 26 Metal Elements in Infant Formula

ZHANG Leilei, WANG Yan, ZHANG Chunlin, SHEN Lu, ZHANG Yan

2017, 40(3):  16-19.  DOI: 10.15922/j.cnki.jdst.2017.03.004

Asbtract ( )   PDF (1549KB) ( )  

Related Articles | Metrics

Inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were compared for determining the contents of metal elements in infant formula milk powder. The limits of detection (LOD) and quantitation (LOQ) of ICP-MS were established using Sc, Rh and Bi as internal standards. Relative standard deviations (RSDs) for 26 analytes were less than 5.0%, and recoveries from spiked samples were 82.80%-110.80%. Eight metal elements could be simultaneously determined by ICP-AES, whose LOD and LOQ were slightly higher than those of ICP-MS. Furthermore, ICP-AES exhibited a good linearity and spiked recoveries in the range of 91.64%-112.73%. In the end, we concluded that both ICP-MS and ICP-AES had a high precision and a good linearity, but ICP-MS allowed the determination of a wider range of metal elements with lower LOD and LOQ.

Reviews

Progress in Understanding Molecular Mechanisms Underlying Regulation of Pseudomonas Biofilm Formation

XU Yu, LIU Zhenmin, YOU Chunping

2017, 40(3):  20-23.  DOI: 10.15922/j.cnki.jdst.2017.03.005

Asbtract ( )   PDF (1300KB) ( )  

Related Articles | Metrics

Pseudomonas is a genus of bacteria commonly found in contaminated raw milk. This bacterial genus can form a biofilm on equipment surfaces during the production of dairy products which causes equipment corrosion and is difficult to remove. The biofilm formed by Pseudomonas not only promotes the secretion of heat-resistant peptidases but also provides a substrate for the growth of pathogenic bacteria, posing a great risk to the safety of dairy products. This article outlines recent progress in understanding the mechanisms for the regulation of Pseudomonas biofilm formation and the environmental factors affecting Pseudomonas biofilm formation, which is helpful for the prevention and control of Pseudomonas bioflim.

A Survey of Solutions to Dairy Product Safety Problems Based on Industrial Chain Optimization

ZHANG Xianxian, GONG Xiaoju

2017, 40(3):  24-28.  DOI: 10.15922/j.cnki.jdst.2017.03.006

Asbtract ( )   PDF (1579KB) ( )  

Related Articles | Metrics

The dairy industry has a high requirement on industrial chain integration, but in recent years, with the development of China's dairy industry, a series of dairy product safety problems have occurred frequently. China's dairy industry chain is long and complicated, with small-scale and scattered dairy farming at its beginning. The frequent occurrence of dairy product safety problems is due to the lack of effective integration of various links of the industry chain. This article explores in depth existing product safety problems across the dairy industry chain. In view of the hidden danger in the industry chain, we recommend that the quality and safety of dairy products should be improved by enhancing the degree of integration, regulating the quality and safety of supply chain, improving the mechanism to connect the interests of dairy industries and farmers, and urging the government to exert an auxiliary function.

Progress in Sensory Evaluation of Dairy Products

CONG Yijie, MA Rui, WANG Shijie, ZHU Hong, QU Dianling

2017, 40(3):  29-32.  DOI: 10.15922/j.cnki.jdst.2017.03.007

Asbtract ( )   PDF (1316KB) ( )  

Related Articles | Metrics

Driven by the development of modern statistics, physiology and human bionics, sensory evaluation of dairy products nowadays has been increasingly mature and considered highly significant. This article reviews the definition and procedure for sensory evaluation of dairy products as well as the application of sensory evaluation for dairy products. Moreover, further prospects are discussed. The aim of this review is to provide a theoretical basis for sensory evaluation of dairy products.

A Review on the Mechanism of Acid and Bile Salt Resistance of Lactic Acid Bacteria

ZHAO Xiaoxi, WEI Xudan, CHEN Dailing, SUN Lingling, FENG Meiqin

2017, 40(3):  33-36.  DOI: 10.15922/j.cnki.jdst.2017.03.008

Asbtract ( )   PDF (1359KB) ( )  

Related Articles | Metrics

As a common probiotic, lactic acid bacteria must be able to withstand gastric acidity and intestinal bile salts and survive in the human body in large amounts. Nowadays, most studies concerning the mechanism of acid resistance of lactic acid bacteria are focused on the theory of proton pump and alkali production. In addition, the contents of exogenous substances such as glucose, amino acid and fatty acid have a certain effect on its tolerance. The mechanism of inhibition lactic acid bacteria under bile salt stress mainly involves bile salt hydrolase, stress protein and the self-protection ability of its cell membrane. This article reviews the existing literature on the mechanism of acid and bile salt resistance of lactic acid bacteria. The second aim of this review is to explore the factors affecting the acid and bile salt resistance of lactic acid bacteria.

Business Management

Practical Application of Zero Defect Management in Dairy Industries

JIANG Hongbo

2017, 40(3):  37-39.  DOI: 10.15922/j.cnki.jdst.2017.03.009

Asbtract ( )   PDF (1385KB) ( )  

Related Articles | Metrics

Quality assurance is one of the key ideas of production management in an enterprise and improving product quality is important for continuous business operation. The zero defect management requires enterprises to establish the idea of zero mistake, doing everything correctly at the beginning and pursuing perfection in every respect, that is, enterprises should change the past practice of quality inspection after the products leave the factory to prevention and control during the production process for production management. This article reviews practical applications of zero defect management in dairy enterprises. The implementation steps for zero defect management and the achievements made by its use are also outlined at last.