Xue-Jun Liu

Research Progress of Fermentation stater culture on Fermented

Fermented meat products refers to the livestock and poultry meat in the natural or artificial control conditions, the specific beneficial microbial fermentation or the role of enzymes, resulting in a series of biochemical changes and physical changes made after the processing a class of meat products [1].At present, the fermentation meat products are fermented sausage and fermented ham two categories[2]. Fermented sausage, also known as raw sausage, refers to the minced meat (often refers to pork or beef and animal fat with sugar, salt, starter and spices mixed into the casing, after microbial fermentation made of a stable Microbiological properties and typical fermented scented meat products [3].Almost every country have theirselies fermented sausage, such as Germany has Dauerwurst sausage and so on[4].Traditional fermented sausage flavor unique, nutrient-rich.there are still many shortcomings: the production cycle is long and so an.If you add beneficial microorganisms as a starter during the fermentation process, you can improve the product in all aspects of the effect.Therefore, the starter has become the important role in fermented sausage.

Conversion of Metmyoglobin to Bright Red Myoglobin Derivatives by Lactic Acid Bacteria

The aim of this research is to investigate the ability of lactic acid bacteria (LAB) isolated from Chinese dried sausage to convert metmyoglobin into bright red myoglobin derivatives in Mann-Rogosa-Sharp model systems. Of 70 LAB tested, one strain had a typical pink colour (judged by visual inspection) than the control samples and was identified as Weissella cibaria by serial biochemical tests and 16S rRNA analysis. This study provides a potential method for nitrite substitution by preserving or improving the color of meat products. Introduction The color of meat and meat products is key factor affecting purchasing decisions of consumers. Meat color largely depends on the chemical state of myoglobin, a heme-containing protein [1]. Fe (II) myoglobin (nitrosylmyoglobin), an important red myoglobin derivative in cured meat products, results from the interaction between myoglobin and nitric oxide generated from nitrite [2]. Nitrite is critical curing agent because it not only can format a characteristic pink color but also contribute to the cured-meat flavor and inhibit unwanted bacteria [3]. However, nitrite addition can also result in the formation of carcinogenic, teratogenic and mutagenic N-nitrosamines in cured products or in the stomach [3]. Moreover, on the October 26, 2015, The World Health Organization branches IARC announced the investigation reported that processed meat products and red meat carcinogenicity, the processed meat products was assigned to a category 1 carcinogen (carcinogenic), and currently recognized as asbestos, arsenic and tobacco column. Red meat is a category 2A carcinogen, which was identical with chloramphenicol, formaldehyde, PCBs and so on. Therefore, it is imperative to find a nitrite alternative for meat products. The effect of some microorganisms on meat color and the ability of convert metmyoglobin to red myoglobin derivative were observed in recently [4]. To date, however no research has to screen lactic acid bacteria (LAB) that have the ability of nitrite development coloring [5]. Therefore the objective of this study is to isolate and characterize a lactic acid bacteria with the ability of convert metmyoglobin into bright red myoglobin derivatives. Materials and Methods Materials Sample: Chinese traditional fermented meat products (Sichuan sausage) Reagents: Myoglobin lyophilised powder was obtained from Sigma Aldrich Chemical Co. (St. Louis, MO, USA). The peptone, beef extract and yeast extract and all other chemicals and solvents were of analytical grade. 434 Isolation and Screening of Lactic Acid Bacteria (LAB) Strains 25 g fermented meat was added into 225 mL saline and then was homogenized by homogenizer. Serial dilution was done; 0.1 mL of dilution was spread on MRS + CaCO3 agar plates and then were incubated for 48 h at 37°C under anaerobic condition [6, 7]. Selected appropriate dilution, single colonies were picked crossed isolated and purified based on colony color, size, luster and degree of transparency. Subsequently, 70 single colonies LAB strains (Gram-positive, catalase-negative bacteria) were saved by 20% glycerol at -20°C. Secondary Screening of LAB Strains Secondary screening of LAB strains were conducted based on the demonstrated differences of acid production ability, amino acid decarboxylase production activity, L-arg ammonia production ability and antibacterial activity against common food-borne pathogens such as E.coli and S. aureus [2]. MbFe III Conversion in MRS Model Systems The capacity of the saved lactic acid bacteria to convert MbFe III into bright red myoglobin derivatives was assessed as described by Arihara et al. (1993), with a few modifications [7]. A 20 mg/mL horse heart myoglobin solution in 50 mM sodium phosphate buffer (pH 6.5) was heated at 50°C for 30 min to remove any residual enzymes having metmyoglobin reducing activity. The denatured proteins were removed by centrifugation (10,000 × g, 5 min, 4°C) and then the resulting supernatant was sterilized by filtration (0.45 μm pore size; Pall, USA). Metmyoglobin solution was added to tempered (50°C) MRS media to give a final conversation of approximately 2.0 mg/mL. After solidification, agar plates were inoculated. Plates were incubated for 1-2 days at 37°C under aerobic conditions. Meanwhile, overnight cultures were inoculated MRS broth containing metmygolobin. Identification of LAB Analytical Profile Index (API) identification system, including physical, biochemical, and molecular biological characteristics tests, was used for the preliminary identification of the isolated LAB. 16S rDNA sequence analysis was also conducted for LAB strain identification. Lactic acid bacteria physiological and biochemical tests: lactic acid bacteria tube sets biochemical identification kit. 16S rDNA sequence analysis was conducted. Total chromosomal DNA was purified from the LAB strains’ cells growing in proper conditions according to the method used in previous reports, and then used as a template for polymerase chain reaction (PCR) amplification. PCR amplification program comprised 30 cycles, with denaturation at 94°C for 45s, primer annealing at 65°C for 30s and extension at 72°C for 1.5 min. The amplified fragment was sent to Invitrogen Biotechnology (Shanghai) Co., Ltd. for sequencing. Results and Discussion Isolation and Screening of Lactic Acid Bacterial (LAB) Strains 70 bacteria strains were, initially identified as lactobacillus based on gram staining, touch the enzyme reaction isolated from the Sichuan sausage. Secondary Screening of LAB Strains Strain L2 has strong production acid ability, 24 h after can reach 4.40, did not produce mucus, can withstand 6% NaCI and 150mg / kgNaN02. Fermentation arginine did not produce ammonia, did not

Research on Optimization of Production Process of Whole Egg Liquid Egg Dry

In order to improve the egg processing technology innovative applications, this paper researches the main raw material according to the liquid whole egg, cooking experiments made instant food. Hardness, gumminess, cohesion, viscous, chewiness and elastic as measure indicator, and combined with sensory score, the effects of carrageenan, water, cooking time and cooking temperature on the impact of eggs dry matter were determined. On the basis of single factor experiment, orthogonal experiment was carried out. Results showed that the optimal formula was carrageenan 0.4%, water 20%, cooking time 15 min, cooking temperature 120 °C. Under this condition, the sensory score was the highest. Introduction Egg is one of food which human being eats frequently, not only it contains rich high quality protein and lipid, but also provides people with vitamins and minerals [1]. The nutrition of the egg is the essential part of the body, it plays an extremely important role, such as repair tissue, formation of new tissue, energy consumption, and involved in the metabolism of complex process, etc. Egg yolk contains rich lecithin, it can decrease the cholesterol, soften the blood vessels, decrease the blood pressure and improve the memory effect [2-4]. And the digestion rate of egg’s high quality protein is as high as 98%, it is the highest among the milk, meat, rice, bread and other food [5-6]. The traditional eating way is mainly limited to fried, steam, boil and other cooking ways, and processing marinated egg, salt egg, preserved egg, and other products, so that they have poor taste and nutrition [7]. In recent years, with the progress of food industry technology and the innovative application of the processing technology, the new type of processed products egg dry gets the favour of consumers due to it’s easy to eat and carry, delicate taste, long shelf life, product novelty and other characteristics [8]. Materials and Methods Experimental Materials Egg (Wal-mart, Changchun), water, salt, sugar, carrageenan, soy protein, white pepper, ginger, onion juice are all of food grade. Instrument and Equipment Air-cooled freezers (Sartorius Co., Ltd, Beijing); electronic balance (Sartorius Co., Ltd, 365 BAS124S-CW, Beijing); V8 vacuum packaging machine (Taiwan well-off machinery Co., Ltd.); TMS-Pro Texture Analyzer (US FKC Co., Ltd); Universal chopping machine (Stephan Co., Ltd). Test Content and Method Basic Formula. (whole egg liquid: soy protein 20:1, salt 3%, sugar 1.2%, white pepper 0.2% , ginger juice 1%, onion juice 0.8% ) Operation Process. Raw material → cleaning → shell breaking → additive → mixing → filter → degassing → cooking → vacuum packing → sterilization → cooling → finished products Standards for Product Quality Criteria for Sensory Evaluation. It composed of ten experienced staff assessment team, conducted by sensory assessors scoring evaluation. Sensory quality assessment criteria are shown in table 1. Table 1. Standards of Sensory Evaluation. The evaluation index Grading Score Colour and luster (total score 20 points) Outside surface is yellow and uniform color 15~20 Outside surface is yellow, inside some color is not uniform 10~14 Surface color is not even, white and yellow 5~9 State of organization(total score 50 points) Elasticity is moderate, the surface no cracks. Better hardness, cutting surface smooth level off, without bubbles or smaller bubbles and uniform distribution 41~50 Elasticity is moderate, the surface no cracks. Has the high hardness, cutting surface smooth, there are air bubbles 31~40 Elasticity is poorer, the surface has crack. Low hardness, rougher cut, bubbles. 21~30 taste(total score 50 points) Taste mellow, spices (total integration, have full-bodied egg fragrance, no peculiar smell 21~30 Egg flavor slightly, spices, but no peculiar smell 11~20 No egg flavor, spices (no integration, have peculiar smell 1~10 Experimental Design Single-factor Design. Table 2. The Single Factor Level Table. Level Content of the carrageenan(%) Content of the water(%) Cooking time (min) Cooking temperature (°C) 1 0.2 10 10 100 2 0.3 15 15 110 3 0.4 20 20 120 4 0.5 25 25 130 5 0.6 30 30 140