Effect of the type of manufacture (homemade or industrial) on the biochemical characteristics of Chorizo de cebolla (a Spanish traditional sausage)

Chorizo de cebolla is a dry-fermented sausage abundantly produced and consumed in Galicia (NW Spain). The aim of this article is to perform an exhaustive biochemical characterisation of this sausage variety and to try to differentiate between the homemade and the industrially manufactured product on the basis of biochemical parameters.The gross chemical composition and the main physico-chemical, proteolytic, lipolytic and fat auto-oxidative parameters were determined in 30 homemade samples and 20 industrially manufactured samples of Chorizo de cebolla. Compared to other raw-cured sausages that have been studied, Chorizo de cebolla is characterised by low contents of protein (N × 6.25), ash and NaCl, and high contents of fat; its average content of hydroxyproline is clearly much higher than the amount determined in other raw-cured sausages.Homemade Chorizo de cebolla showed statistically significant differences to industrially manufactured Chorizo de cebolla in hydroxyproline and nitrates content and in titratable acidity, and pigment conversion percentage (which were higher in the industrially manufactured Chorizo), and in total carbohydrate content and values of pH (that were higher in the homemade Chorizo). Using discriminant analysis techniques, both types of Chorizo can be differentiated based on the values of these six parameters.     

Shelf-life extension on fillets of Atlantic Salmon (Salmo salar) using natural additives,superchilling and modified atmosphere packaging

The effect of natural additives, superchilling, and modified atmosphere packaging (MAP) on the shelf-life of Atlantic Salmon (Salmo salar) fillets was investigated. The variables analyzed were: gas concentration (CO₂:N₂), gas-to-product volume (g/p) ratio and type of natural additive. Experiments were monitored by sensory, chemical, and microbiological analyses. Natural additives did not improve salmon shelf-life. The greatest extension of shelf life was reached by a combination of superchilling and MAP. The samples with the highest CO₂ concentration (90%) and g/p ratio of 2.5 showed the highest shelf-life: 22 days vs. 11 days (control sample). Microbial analysis determined the ultimate shelf-life.     

Effect of commercial starter cultures on physicochemical characteristics,microbial counts and free fatty acid composition of dry-cured foal sausage

The need for high-quality safe products has resulted in the use of starter cultures for the production of dry-cured sausages. The aim of this work was to evaluate the effect of commercial starter cultures on the physicochemical properties, microbiological counts and free fatty acid composition during the ripening of dry fermented foal sausages. Microbial counts revealed that, although initial counts of Enterobacteriaceae were similar in the four batches (3.48 log CFU/g), this microbial group exhibited a strong decrease during the ripening of inoculated sausages, and reached values below 1 log CFU/g in the final product, whereas the counts of Enterobacteriaceae in the control sausages were 2.41 log CFU/g at the end of the ripening. In general, physicochemical parameters were not affected by the use of starter cultures, but by the ripening time, with the exception of pH values, since the inoculation of starter cultures resulted in a stronger acidification during the first two weeks of production, with pH values below 5 in inoculated batches. Finally, statistical analysis revealed that free fatty acid (FFA) profile was not significantly affected by starter cultures and it might therefore be considered that the major release of FFA was probably due to endogenous lipases. In conclusion, it seems that the inclusion of starter cultures contributes to improve the hygienic quality of foal sausages without significant effect on lipolysis, texture and appearance.     

Chemical and sensory characteristics and microbiological safety of fresh finely chopped parsley packed in modified atmosphere

For the determination of the shelf-life of minimally processed finely chopped parsley two assays were performed packing the product under passive and active atmosphere. Quality parameters were assessed for 13–15 d on the samples stored at 5 °C and 90% relative humidity: chemical characteristics, sensory characteristics and gas concentration inside the bags. Microbiological analyses were performed for the samples of the second process. Under the studied conditions parsley packed in passive atmosphere resulted in a better product when compared to the one packed in an active modified atmosphere showing quality and stability for a 6 d period.     

Dynamics of the yeast flora in artisanal country style and industrial dry cured sausage (yeast in fermented sausage)

Yeast can act as an adjunct in the sausage-making process as a way to prevent or reduce excessive acidification during aging of products. Two kinds of process were studied: industrial and artisanal country style. Three hundred and fifty three yeast strains were isolated, characterized and identified by biochemical and molecular techniques. Evolution of pH, Aw, weight loss, bacterial growth and proteolytic and lipolytic activity was studied. Final pH in artisanal country style product was higher than in the industrial sausage. There was little difference noted between final weights of products but it was observed a lower yeast count in artisanal country style sausage. No relevant difference was observed in center or surface yeast count in both products. The biochemical assay identified six yeast genera and the molecular test confirmed four different genera, and further analysis showed predominance of the genera Debaryomyces. The relations between this four genera and isolation point (center or surface of sausage) were established. The presence of yeast in the center/surface of ART sausage was more prevalent than in the same places of industrial sausage.     

Biochemical characteristics of dry-cured lacón (a Spanish traditional meat product) throughout the manufacture, and sensorial properties of the final product. Effect of some additives

The gross composition, the main physicochemical parameters, the proteolytic changes and the characteristics of the fat throughout the manufacture process, and the sensorial characteristics of the final product, were studied in dry-cured lacón, a traditional dry-salted and ripened meat product made in the north-west of Spain from the fore leg of the pig following a similar technological process to that of dry-cured ham. The effect of the use of additives (glucose, sodium nitrite, sodium nitrate, sodium ascorbate and sodium citrate) was also studied.In comparison with other dry-cured meat products made from whole meat pieces, dry-cured lacón is characterised by the low moisture contents, the high pH values, and the low transformation of the pigments. The proteolytic and lipolytic processes throughout the manufacture of this product were not intense. Except for the total carbohydrate and nitrate contents, and the percentage of transformation of the pigments, which were significantly (P < 0.05) higher in the batches processed with additives, the use of additives did not influence the biochemical modifications that occur throughout the manufacture process of the dry-cured lacón. Regarding the sensorial characteristics, the use of additives seems to improve the colour and the odour of the final product.     

Food safety aspects of fresh Nile perch (Lates niloticus) fillets from Lake Victoria imported to the European market: Helminth parasites and microbiological status

Nile perch (Lates niloticus) is a popular, usually low priced food fish in many countries worldwide, and the most important export fish from Lake Victoria and its adjacent countries Uganda, Tanzania and Kenya. Despite its high import figures, the constantly increasing demand within the EU for ‘new’ fish species and the results of initial studies indicating high coliform bacterial loads, food safety aspects regarding its microbiological as well as parasitological status have been hitherto widely neglected. In the present study imported fresh fish fillets as well as superchilled fish from a German retail market and a Dutch wholesaler were examined to evaluate the current microbiological and parasitological quality. A total of 200 fresh fillets as well as 20 superchilled fish (beheaded, eviscerated, descaled) samples were screened for the presence of helminth parasites by visual inspection, candling, the UV-press method and artificial digestion method. The study includes as well a quantitative test on the recovery rate of metacercarial cysts. Microbial assessment was performed on ten fresh fillets and on the skin and tissue of 20 superchilled fish. Helminth parasites were neither detected in the edible parts nor in the skin of imported products. Results of the microbiological examination revealed low levels of bacterial contamination of superchilled fish samples, whereas high total viable counts and high levels of naturally present bacterial pathogens of the genus Aeromonas spp. and Pseudomonas spp. were identified from the fresh fillets. Our findings indicate that hygienic production conditions have improved in comparison to previous studies. As total viable counts as well as specific spoiling bacteria were high in fresh fillets, we recommend adequate heat treatment of fresh Nile perch fillets before consumption.     

Shelf-life of pacific white shrimp (Litopenaeus vannamei) as affected by weakly acidic electrolyzed water ice-glazing and modified atmosphere packaging

The combined effect of weakly acidic electrolyzed water (WAEW) ice-glazing and modified atmosphere packaging (MAP) treatment on the quality of pacific white shrimp (Litopenaeus vannamei) during frozen storage was investigated in terms of microbiological activity, TVBN, TMA and TBARS content, texture, color and volatile flavor analysis. As a result, significantly (p < 0.05) higher inhibitor effects on total aerobes and Staphylococcus aureus were observed in WAEW ice-glazed shrimp packaged in 40% CO₂ + 10% O₂ + 50% N₂ or in 30% CO₂ + 20% O₂ + 50% N₂ than the water- and WAEW ice-glazed batches. Additionally, chemical analysis results showed that WAEW ice-glazing combined with MAP was highly effective in maintaining lower TVBN, TMA and TBARS values in frozen shrimp, perhaps due to the synergistic effect of antibacterial and antioxidant abilities. On the other hand, the texture, L^*, and a^* results also confirmed that this combined treatment effectively retarded the degradation of the physical structure of shrimp muscle and showed a positive effect on the stability of color during frozen storage. However, the presence of WAEW ice-glaze showed a negative effect on the volatile flavor of thawed shrimp due to the volatile chlorine and chlorine dioxide, but no significant effect in the cooked samples. Overall, the application of WAEW ice-glazing combined with MAP on peeled frozen shrimp is advisable to achieve better quality maintenance and extend the shelf-life of refrigerated products.     

石油化工厂火炬设计及运转操作的安全性（一）

较详细地论述了火炬系统的流程,火炬头的结构形式与产生的噪声;火焰辐射热强度对人体、设备及材料的危害;火炬系统可能发生的危险事故及原因,在设计和运转操作方面的预防措施。     

Effect of nutmeg (Myristica fragrans) essential oil on the oxidative and microbial stability of cooked sausage during refrigerated storage

This paper examines the oxidative and microbial stability of cooked sausages, produced with the addition of 10 ppm (NO1) and 20 ppm (NO2) nutmeg (Myristica fragrans) essential oil. Instrumental parameters of color (CIE L*, CIE a* and CIE b*), Thiobarbituric acid-reactive substance (TBARS) values, microbial profile and sensory properties of aroma have been determined on the 1st, 30th, 45th, and 60th day of storage. Addition of the nutmeg essential oil had no effect on the color of cooked sausages. At the end of the storage, NO2 sausages had the best oxidative and microbial stability. TBARS values of NO1 and NO2 sausages were 1.21 mg MDA/kg and 0.95 mg MDA/kg, respectively, and were significantly lower (P < 0.05) compared to control (1.53 mg MDA/kg). Total number of aerobic mesophilic bacteria was lowest in NO2 sausages (78.3 cfu/g) and highest in control (185 cfu/g). After 45 and 60 days of storage, sensory properties of aroma of NO1 (4.21; 3.92) and NO2 sausages (4.39, 4.28) were better compared to those in control (4.07, 3.25). Hence, the addition of nutmeg essential oil in amount of 20 ppm can be successfully applied in order to extend the shelf life of cooked sausages.     

非数字原生企业数字化转型实践与认识

在工业4.0背景下,企业数字化转型已成为必然。对比数字原生企业,非数字原生(传统)企业实施数字化转型具有数据基础薄弱、技术路线适应性差、保障能力不足的特点。在阐述企业数字化转型基本认识基础上,从基层实践认识出发,系统地论述非数字原生企业数字化转型难点、数据管理、技术路线、组织保障,总结了“3专+3A”数据治理方法,明确以“云化+平台化+云边协同+敏捷开发与交付”的技术路线,引入V&V“第三只眼”做质控保障,并建议组建专职队伍,以协助公司决策层推动、质控、巩固、优化数字化转型成果。应用实践表明,研究成果可为同类型企业的数字化转型工作提供参考。     

Environmental aspect of storage of acid tars and their utilization in commercial petroleum products (Review)

Data on the formation and disposal of acid tars, as well as on the development of ways of their utilization into commercial petroleum products, are summarized. An analysis of the relevant literature over the past 60 years has made it possible to objectively assess the environmental situation that has developed as a result of the disposal of acid tars in storage ponds in Russia. The risks of harmful effects of heavy refinery wastes on humans and animals were estimated.     

Evaluation of ozone efficacy on the reduction of microbial population of fresh cut lettuce (Lactuca sativa) and green bell pepper (Capsicum annuum)

Raw vegetables are usually contaminated by a variety of microorganisms. Post-harvest microflora differs considerably, reflecting environmental and handling conditions and might compromise the safety of the product and the consumer's health.Dipping or rinsing of vegetables in bleach solution is a common practice employed by the retailers and catering companies in order to minimize the initial bacterial load on the surface of vegetables. Rinsing or dipping vegetables in water saturated with ozone could be an alternative environmental friendly and safer process since no harmful by-products or residues are formed.Lettuce (Lactuca sativa) and bell peppers (Capsicum annuum) dipped in chlorinated water (20 ppm) resulted in 1 log decrease of the total microbial count in the first 15 min. Immersing of vegetables in water pre-saturated with ozone (0.5 mg/L) did not make any difference because the total microbial count decreased approximately 0.5 log for the same time. Sanitation treatments were most effective when vegetables were dipped in continuously ozonated (0.5 mg/L) water, leading at about 2 log of microbial load decrease in the first 15 min and 3.5 log after 30 min of exposure. The best results were achieved in the case of bell pepper, as its smooth uniform surface allows higher ozone effectiveness. Bacteria reduction kinetics in continuous ozonation trials were fitted satisfactorily by a Weibull-based model allowing a better optimization of the process.     

Effect of washing and disinfecting containers on the microbiological quality of fresh milk sold in Bamako (Mali)

The present study aimed to improve the microbiological quality of the milk, from the cow’s udder to the selling point by container washing and disinfecting. The total counts (TC), Enterobacteriaceae counts (EBC) were used as quality indicators.The results showed a significant decrease of milk flora at the selling point, from 1.6 × 10⁷ ± 1.3 × 10⁷ (control) to 4.8 × 10⁵ ± 0,8 × 10⁷ (intervention) colony forming units per ml (cfu ml⁻¹) for TC and 1.2 × 10⁶ ± 1.1 × 10⁶ (control) to 0.9 × 10⁴ ± 1.1 × 10⁴ (intervention) cfu ml⁻¹ for EBC. The study suggests that in milk production area, besides udder infection and water quality, hygiene behaviour with respect to hand washing, container’s cleaning and disinfection are the key areas that remain of relevance to milk hygiene intervention.     

Detection of recombinant DNA of genetically modified (GM) soybeans in heat-treated GM soybeans and commercial natto

We examined the detection of recombinant DNA of genetically modified (GM) soybeans in heat-treated GM soybeans and commercial natto. Genomic DNA was extracted from heat-treated GM soybeans and natto using the cetyltrimethylammonium bromide (CTAB) or alkaline lysis methods. First, primer pairs amplifying the junction region between CTP and CP4EPSPS in recombinant soybean were designed; they gave PCR products of band sizes, 100, 110, 120, 130, 140, and 150 bp. When DNA solution extracted from heat-treated GM soybeans by the alkaline lysis method was applied to polymerase chain reaction (PCR), PCR products of the expected 100, 110, 120, 130, 140, and 150 bp were detected by agarose gel electrophoresis. However, PCR products were not detected in DNA extracted from heat-treated GM soybeans by the CTAB method, and no PCR products were detected in either extract from natto. Next, PCR using primer pairs amplifying the junction region between NOS and part of CP4EPSPS were designed; they gave PCR products of 100, 110, 120, 130, 140, and 150 bp. The expected PCR products from all DNA extracts were detected (heat-treated GM soybeans by CTAB, 100–140 bp; heat-treated GM soybeans by alkaline lysis, 100–150 bp; natto by CTAB, 100–130 bp; and natto by alkaline lysis, 100–150 bp). These results indicate that judicious selection of DNA extraction methods and target sequences is important to detect DNA from natto and recombinant DNA can be detected in natto.     

Biogenic amine content and aromatic profile of Salama da sugo,a typical cooked fermented sausage produced in Emilia Romagna Region (Italy)

Salama da sugo is a fermented sausage from Ferrara tradition, subjected to a long ripening period (4–6 months). It can be consumed after cooking, served with its sugo, i.e. the liquid extracted by cooking process. Besides to pork meat and fat, also NaCl, curing salts, sugar, spices and almost 15% of red wine are added. The aim of this research was the microbial and aromatic profile characterization of Salama da sugo during ripening. The product was sampled in order to study chemico-physical parameters, microbial population composition (Enterobacteriaceae, lactobacilli, enterococci, micrococci and staphylococci, including coagulase positive, fungi, total mesophilic bacteria), biogenic amine content and aromatic profile. The results showed that this traditional product was characterized by a complex aroma.Moreover, the biogenic amine concentration was low (less than 200 mg/kg for tyramine, about 50 mg/kg for cadaverine and putrescine while histamine was below the detection limit).