Extraction of Bitter Acids from Hops and Hop Products Using Pressurized Solvent Extraction (PSE)

The EBC method 7.7, currently used for determination of bitter acids in hop products, is a time‐consuming and laborious extraction technique. In this paper, our aim was to propose a new extraction method based on Pressurized Solvent Extraction (PSE) sometimes also called Pressurized Fluid Extraction (PFE) or Accelerated Solvent Extraction (ASE). Compared to conventional extractions, PSE offers a number of important benefits. PSE on OnePSE^® automated extractor was used for extraction of α‐ and β‐acids from hops and hop products and the parameters influencing extraction efficiency and the influence of the sample preparation method were studied. The quantitative determination of α‐ and β‐acids in the extracts was accomplished by using an HPLC apparatus equipped with diode array detector. The experimental results were compared with those obtained by the standard EBC 7.7 method and the two methods were found to be fully compatible     

猪肉脂肪氧化酶在高压结合热处理过程中失活动力学模型

为了解猪肉高压加工过程中脂肪氧化酶(lipoxygenase,LOX)活性的变化规律,以猪背最长肌为原料,经不同压力(200~700 MPa)、温度(20~60℃)结合处理后,研究LOX失活常数的变化规律,并分别用Arrhenius和Eyring方程为基础来建立LOX失活的动力学模型。结果表明,当处理温度不变时,失活常数随压力的增加而增加;同样,当处理压力不变时,失活常数随温度升高而增加。Arrhenius和Eyring方程分别适用于整个研究的温度区间和压力区间,分别以两者为基础可以建立LOX失活的动力学方程,两个方程的拟合程度均较高,决定系数分别达到0.989和0.965。因此在一定的处理温度(20~60℃)和压力(200~700 MPa)范围内,猪肉高压结合热处理过程中LOX活性的变化可以用以Arrhenius和Eyring方程为基础建立的数学模型进行预测。     

Effects of transportation time,distance, stocking density,temperature and lairage time on incidences of pale soft exudative (PSE) and the physico-chemical characteristics of pork

The study determined the effects of transportation time, distance, stocking density, temperature and lairage time on incidences of PSE and pork quality. Frequencies of PSE cases in stocking density categories within transport duration classes were determined. General linear models, regression and the principal component (PC) analysis were used to analyse the data. Highest incidences of PSE were recorded in autumn season while lowest incidences were recorded in the spring season. Transportation time and stocking density significantly affected pH_u and ultimately PSE incidences although there were no interactive effects. Highest risks of PSE occurrence were observed with more space allowance. The highest incidences of PSE were observed for animals that had travelled for two hours while the PSE cases were lower in animals that travelled for longer times. Distance travelled and transportation time had significant effects (P < 0.05) on thawing loss (TL) % of pork. No relationships were reported between the other pre-slaughter variables and pork quality attributes. With the exception of transportation time and distance travelled which had a positive relationship with TL%, variation in other pre-slaughter variables did not affect meat quality variables. The risks of PSE occurrence were dependent on stocking density and transportation time.     

Effects of onion on physicochemical properties,lipid oxidation and microbial growth of fresh pork patties

Onions with or without heating (100 °C, 30 min) were extracted with water or methanol, and antioxidant and antimicrobial activities of onion extracts were evaluated. Product characteristics of fresh pork patties containing various onion extracts were measured during refrigerated storage. Water extracts of onions showed higher extraction yield and iron chelating ability than methanol extracts (P < 0.05), whereas, the latter was more effective than the former in phenolic compounds and reducing power (P < 0.05). The addition of onion extracts [water extract from fresh onion (WEFO), methanol extract from heated onion (MEHO) and their combinations (WEFMEHO)] to pork patties decreased redness, increased yellowness, and inhibited lipid peroxidation (P < 0.05). One per cent of WEFMEHO in pork patties had antioxidant activities as effective as butylated hydroxyl toluene (BHT, 0.01%). Redness and yellowness decreased and increased with the addition of onion extract, respectively (P < 0.05).     

Effects of Eubacterium coprostanoligenes and Lactobacillus on pH, Lipid Content, and Cholesterol of Fermented Pork and Mutton Sausage-Type Mixes

Pork and mutton sausage-type mixes produced using Eubacterium coprostanoligenes with or without Lactobacillus as starter culture showed changes in pH, cholesterol and lipid content. Viability of E. coprostanoligenes was assessed by culturing samples from each treatment and analyzing for coprostanol, a cholesterol metabolite. The pH and/or cholesterol decreased (P < 0.05) in the sausage-type mixes inoculated with E. coprostanoligenes or Lactobacillus or their combinations. Variability in lipid content was observed among and within treatments. Very low (6.2 μg/g dry matter) concentrations of coprostanol were produced in sausage-mixes and cultures except when inoculated with 2.0 g of E. coprostanoligenes (from 8.2 to 130.6 μg/g dry matter).     

笋干菜糯米营养保健香肠的开发研究

研究了笋干菜营养香肠的生产工艺,探讨了影响其质量的因素:笋干菜的添加量、糯米的添加量、糯米的颗粒度及肥、瘦肉的比例。并在此基础上采用正交实验得出了最佳工艺条件和配比,结果表明:五花猪肉79%,糯米用量15%,笋干菜用量6%,肥、瘦肉比例2:8,糯米颗粒度30目时香肠质量最佳。     

Thermal Inactivation of Salmonella spp. in Chicken Broth, Beef, Pork, Turkey, and Chicken: Determination of D- and Z-values

ABSTRACT: The heat resistance of 35 Salmonella strains was determined at 55 to 65°C. No correlation between the heat resistance and the origin of the Salmonella spp. could be established. D-values in chicken broth, using a linear regression, of an 8 Salmonella serotype cocktail were 4.87, 2.72, 1.30, and 0.41 min at 55, 58, 60 and 62°C, respectively. Using a linear model, the D-values ranged from 4.86 min at 55°C to 0.38 min at 62°C. When the 8 Salmonella serotype cocktail was heated in meat, D-values at the common test temperatures of 58 and 60°C calculated by both approaches were significantly higher (p < 0.05) than those observed in chicken broth.     

Effect of the combination of various NaCl levels and soy protein isolate on the quality characteristics of smoked pork loins

The objectives of this study were to evaluate the physicochemical, textural and sensory properties of smoked pork loins (PL) containing various levels of NaCl (0.0–2.0%) alone or in combination with soy protein isolates (SPI; 1.0%). The pH values, moisture, fat, and protein contents (%) of smoked PL were 5.97–6.17, 63.3–69.1%, 2.64–4.26%, and 20.2–26.6%, respectively. Increased NaCl levels increased moisture contents (%) and sensory scores, as well as reduced Hunter redness and yellowness and cooking loss (CL, %) (P < 0.05). A NaCl level of 1.0% had resulted in a CL (%) level similar to those at regular‐salt levels (1.5% and 2.0% NaCl). When 1.0% SPI was incorporated with smoked PL, the NaCl level of 0.5% was also similar to the CL (%) at higher NaCl levels and improved sensory scores. Thus, a NaCl level of at least 1.0% was required for the manufacture of smoked PL; however, smoked PL could be manufactured with 0.5% salt when 1.0% SPI was included as part of the manufacture of smoked PL to effect quality characteristics similar to those achieved with regular‐salt (1.5% and 2.0% NaCl) smoked PL.     

几种肉脯的加工工艺

详细介绍了我国几种肉脯的加工工艺、配方和工艺要点。     

Freeze/thaw Stability of Cooked Pork Sausages as Affected by Salt, Phosphate, pH, and Carrageenan

The effects of κ, ι, or λ carrageenan (CGN), sodium tripolyphosphate (STPP), chloride salts, and meat pH on the freeze/thaw stability of cooked pork sausages were investigated. STPP decreased thaw drip (TD) and increased hardness for all treatments regardless of type of salt or CGN. KCI did not affect the texture of control samples in the presence of STPP, but decreased the functionality of κ- and ι-CGN. Increased meat pH increased the hardness and decreased thaw drip for all CGN treatments, except for λ-CGN, which remained unchanged. k- and ι- CGN increased moisture retention of sausages prepared from low-pH meat.