Effect of acid whey on physicochemical characteristics of dry‐cured organic pork loins without nitrite

The present study deals with the effect of acid whey (AW) on physicochemical properties of non‐nitrite organic dry‐cured pork loins. The loins were divided into three experimental batches: with the curing mixture (C), with sea salt (S) and with sea salt combined with AW (SW). The evolution of physicochemical properties, colour, fatty acid profile and microbiological quality were assessed at 0, 30 and 90 days of refrigerated storage. Physicochemical parameters of dry‐cured organic loins were significantly (P < 0.01) affected by treatment, storage time and the interaction between them. Sea salt in combination with AW was the most successful at reducing the browning reaction involved in the formation of dark colour in dry‐cured loins. Significant reduction in a* value (P < 0.05) caused by replacement of curing salt by sea salt has been less pronounced in sample with AW. Storage diminished (P < 0.01) initial differences in profile of SFA, MUFA and n‐3 induced by treatment method. AW added to uncured loins was able to protect PUFA against oxidation comparable to nitrite. The highest count of lactic acid bacteria (LAB) in dry‐cured loins with AW was accompanied by their lower pH (P < 0.05).     

Comparative studies on lipid oxidation of organic model sausage without nitrite produced with the addition of native or autoclaved mustard seed and acid whey

The objective of this work was to evaluate the influence of the addition of native and autoclaved mustard seed (AMS) with combination of acid whey (AW) on the stability of organic model sausages during 30 days of vacuum storage by measuring primary and secondary products of lipid oxidation, the changes in the fatty acid composition, oxidation–reduction potential and antioxidant capacity. Briefly, the addition of AW (5%) with combination of AMS (1%) significantly increased the capacity of sausages to capture the radical cations 2,2‐azinobis(3‐ethyl‐benzothiazoline)‐6‐sulphonate at 1 day of storage which suggests that autoclaved mustard possessed significantly higher amount of phenolic acids compared with native mustard. The salted samples with mustard seed addition characterised by lower oxidation–reduction potential values (264.5–302.1 mV) during the whole storage period compared with control‐cured sample (307.3–330.5 mV). Results of conjugated dienes (CD) measurements indicated that salted meat product samples with mustard seed addition were characterised by significantly lower CD concentration (1.12–1.90 μmol mg^?1 meat product) compared with control‐cured sample (1.86–2.55 μmol mg^?1 meat product). The AW and mustard seed added to uncured sausage were able to protect polyunsaturated fatty acids against the oxidation comparable to nitrite.     

Effect of plant polyphenols and ascorbic acid on lipid oxidation,residual nitrite and N‐nitrosamines formation in dry‐cured sausage

The effects of green tea,grape seed polyphenols and ascorbic acid on pH, water activity (a_w), microbiological counts, TBARS, residual nitrite and N‐nitrosamines were determined in dry‐cured sausages during the ripening period. Results showed that TBARS increased gradually during ripening (P < 0.05), but were significantly reduced with plant polyphenols and ascorbic acid (P < 0.05). Green tea polyphenol (GTP) was most effective (P < 0.05) in reducing TBARS. Plant polyphenols and ascorbic acid significantly decreased residual nitrite, ascorbic acid being most effective (P < 0.05). The amount of N‐nitrosamines increased during ripening, but was significantly reduced with plant polyphenols and ascorbic acid (P < 0.05). Plant polyphenols had no significant effects on moisture content, a_w, pH or microbiological counts in dry‐cured sausage during ripening (P > 0.05). It was concluded that plant polyphenols and ascorbic acid were effective in maintaining the quality and safety of dry‐cured sausages.     

The use of bulgur as a meat replacement: bulgur‐sucuk (a vegetarian dry‐fermented sausage)

In this study, bulgur was used to produce a new sucuk (Turkish dry‐fermented sausage) as a vegetarian product. Yellow and black/brown bulgurs were mixed into the sucuk dough as fat and meat imitations respectively. Instead of animal fat, olive oil was used for lubrication. Nitrite and nitrate were not added to the recipe. The bulgur‐sucuk was ripened at 60–95% relative humidity and 18–25 °C over 15 days. During ripening, pH, moisture content and textural (hardness, adhesiveness, springiness, cohesiveness, gumminess, chewiness and resilience), sensory (flavour, colour, cutting and overall scores) and colour (Hunter L, a, b, yellowing index (YI), total colour difference, hue angle, chroma and browning index values) attributes were monitored. The pH and moisture content of the bulgur‐sucuk were 5.81 and 493 g kg^?1 respectively before ripening and decreased to 4.14 and 280 g kg^?1 during ripening. The colour values L, a, b and YI decreased significantly (P < 0.05) to 33.03, 7.67, 11.63 and 80.70 respectively during ripening. Some of these decreases in colour values were expected owing to the lack of nitrite and nitrate. All instrumentally measured textural properties of the bulgur‐sucuk increased significantly (P < 0.05) during ripening. From the results of the parameter measurements and sensory evaluations, bulgur appears to be suitable as a meat replacement when used in a dry‐fermented formulation. Copyright © 2006 Society of Chemical Industry     

Suitability of acid whey for fermented and fresh-pack cornichon pickle production

Suitability of acid whey (AW) as brine media in fermented and fresh-pack cornichon pickle production was investigated. Fermented and fresh-pack pickles were produced with AW and vinegar (control). Microbiological, textural, colour and sensory properties of the pickles were monitored during 12-wk storage at room temperature. Fermented and fresh-pack pickles manufactured with AW exhibited higher total solids content than the pickles manufactured with vinegar. Acid whey as pickling media increased the development of presumptive lactococci species both in fermented and in fresh-pack pickles. This study shows that AW is a suitable pickling media for fermented and fresh-pack cornichon pickle manufacture.     

Quality characteristics of a non‐fermented dry‐cured sausage formulated with lemon albedo

Dry‐cured sausages were treated with two types of dehydrated lemon albedo (raw and cooked) at five concentrations (0–100 g kg^?1 in 25 g kg^?1 increments). Several physical and chemical analyses were made during the drying stage, and compositional, textural and sensory analyses were conducted on the finished products. The addition of albedo improved the nutritional properties as a result of fibre addition and may have beneficial effects due to the presence of active biocompounds as evidenced by a decrease in residual nitrite levels and delayed oxidation (based on TBARS values). The sensory properties of samples that resembled the control sausages were those that contained up to 50 g kg^?1 dehydrated raw albedo and 75 g kg^?1 dehydrated cooked albedo. Copyright © 2004 Society of Chemical Industry     

Effect of selected strains of Debaryomyces hansenii on the volatile compound production of dry fermented sausage “salchichón”

Different biotypes of Debaryomyces hansenii, characterized by mitochondrial DNA (mtDNA) restriction analysis, were inoculated in dry fermented sausages to evaluate their influence as single starter culture on volatile compound generation throughout the ripening process. Similar evolution of physicochemical parameters and microbial population was observed in both uninoculated and inoculated sausages. The tested biotypes modified the volatile compound profile of sausages specially in esters, branched alcohols and aldehydes. The biotype of D. hansenii with the E mtDNA restriction pattern is the most suitable to be used as starter culture since it produced volatile compounds involved in flavour development of dry-cured meat products such as 3-methylbutanol, 3-methylbutanal and 2-propanone. Moreover, the use of D. hansenii strains with the B, C2 and E mtDNA restriction patterns, as a mixed starter culture, should be also considered to generate low amount of sulphur compounds in dry-cured meat products.     

复合发酵剂对羊肉发酵香肠亚硝酸盐残留量和品质的影响

以羊肉为原料不添加发酵剂、添加市售发酵剂和复合发酵剂(植物乳杆菌与肉葡萄球菌混合发酵剂比为1∶3)采用同种工艺生产三组发酵香肠。研究三组羊肉发酵香肠发酵和干燥成熟过程中的p H、Aw、色差、亚硝酸盐(NIT)含量变化以及成品的质构特性。结果显示:发酵过程中,三组发酵香肠的p H、Aw和e值均下降,混合发酵剂组p H迅速降低为4.7,低于对照组和市售发酵剂组,其NIT含量为0.66mg/kg,低于对照组和市售发酵剂组的0.79、0.8mg/kg;成熟结束时,三组的p H和e值开始上升,混合发酵剂组的Aw下降极显著(p<0.01)快于市售发酵剂组和对照组,并且三组各项质构指标除黏聚性外均差异极显著(p<0.01),最终对照组、市售发酵剂组、混合发酵剂组发酵香肠的NIT含量分别为1.38、1.46、1.26mg/kg。整体上,混合发酵剂香肠品质优于其他两组。      

营养鹅肝肠的研制及其营养价值分析

以鹅肝为原料,添加橄榄油、玉米淀粉、鹅肉,采用感官评定、质构性质及流变学等考察指标,通过单因素实验和正交实验,优化得到鹅肝肠的最佳工艺配方,并测定其营养成分。结果表明,以橄榄油15%、玉米淀粉6%、鹅肝50%为主要原料时,研制的鹅肝肠色泽均匀,肠体饱满,有弹性,风味协调;该鹅肝肠含13.12%蛋白质,必需氨基酸含量2.315 mg/100 g,单不饱和脂肪酸比例高达52.79%,n-6/n-3比率较低,铁含量为476 mg/kg、钙380 mg/kg、锌241 mg/kg。由此可见,研制出的鹅肝肠更符合人们对安全、健康、高品质食品的追求。     

酸菜中降解亚硝酸盐乳酸菌的筛选、鉴定及其在发酵香肠中的应用

目的:依据多项评价指标筛选亚硝酸盐降解能力强且适用于肉制品发酵的乳酸菌。方法:首先采用添加0.3%Ca CO3的MRS培养基从15份不同产地的农家自制酸菜中筛选乳酸菌,其后以降解亚硝酸盐能力和肉制品发酵剂所需要求为筛选指标对初筛所得乳酸菌进行复筛,并对其进行菌种的分子鉴定。最后以筛选到的菌株为发酵剂制作单菌株发酵香肠,通过检测香肠在发酵和贮藏期间的Na NO2含量来进一步验证所得菌株的实际降解亚硝酸盐能力。结果:筛选到1株降解亚硝酸盐能力优良(降解率为78.77%)且适于肉制品发酵的乳酸菌菌株,16S r DNA全序列分析鉴定为鼠李糖乳杆菌(Lactobacillus rhamnosus GG,ATCC 53103)。香肠发酵实验结果显示,在发酵结束时香肠的Na NO2含量为12.2 mg/kg,低于国家标准。同时,微生物指标检测结果证明了此条件下生产的发酵香肠的质量是安全可靠的。结论:鼠李糖乳杆菌能有效降低发酵香肠中的Na NO2含量,可用于开发成用于生产低亚硝酸盐的健康、安全的肉品发酵剂。      

Distribution and genetic diversity of lactic acid bacteria from traditional fermented sausage

This study was conducted to investigate the distribution and genetic diversity of the native lactic acid bacteria (LAB) population in nem chua, a popular traditional Vietnamese uncooked fermented sausage. A total of 74 LAB isolates were identified and their molecular fingerprints were obtained using repetitive-PCR (rep-PCR) and pulse-field gel electrophoresis (PFGE). The results revealed that the majority of LAB isolates were Lactobacillus plantarum (67.6%), followed by Pediococcus pentosaceus (21.6%). A minority of LAB (9.5%) were Lactobacillus brevis and Lactobacillus farciminis (1.4%). A large genetic plasticity within the same species was also observed. Both rep-PCR and PFGE methods were found to be acceptable regarding reproducibility and reliability. However, this study demonstrated the higher discriminatory power of PFGE compared to rep-PCR, as observed by the higher number of clusters generated (17 and 12 clusters of L. plantarum respectively, seven and six clusters of P. pentosaceus respectively and four and two clusters of L. brevis respectively), and lower percentage of similarity among clusters in PFGE data analysis. These results also revealed that there was not a single LAB strain that was found to predominate in the product. To our knowledge, this is the first detailed analysis of the native LAB population in nem chua. As this traditional sausage is fermented naturally or only with back-slop, knowledge about the native LAB population in the product is very important to understand the microflora that has been active in fermenting the nem chua and to ensure the safety of this uncooked sausage.     

Traditional fermented sausage ‘Nem chua’ as a source of yeast biocatalysts efficient for the production of the aroma compound γ‐decalactone

The yeast ecosystem of Nem chua, a Vietnamese traditional fermented sausage naturally rich in medium‐chain‐length lipid‐derived flavouring compounds, was investigated to select biocatalysts able to produce the C10‐fatty acid‐derived aroma compound γ‐decalactone. The total number of yeast was about 5 × 10⁴ to 4 × 10⁵ CFU g^?1, and eighty four different species were identified from morphological, physiological and 26S rDNA characteristics, with Candida sake and Candida haemulonii being found in all samples. Six strains able to produce γ‐decalactone from castor oil were selected, of which three Yarrowia lipolytica strains were able to produce between 1 and 2 g L^?1 in our study. The strains produced the same amount from the acyl substrate under the form of ester or free fatty acid. Every strain degraded the product at the end of the culture. These high productions make them good candidates for industrial processes and confirm that traditional fermented foods are interesting bioresources for biocatalysts.     

Investigation of the effect of sumac extract and BHT addition on the quality of sucuk (Turkish dry‐fermented sausage)

The effect of sumac extract and BHT (butylated hydroxytoluene) addition on the quality (pH, colour, biogenic amine, TBARS values and sensory attributes) of sucuk (Turkish dry‐fermented sausage) were investigated during the ripening period. Addition of BHT decreased the TBARS value by about 23.7%, whereas sumac extract decreased it by 42.0%. Sumac extract decreased (P < 0.05) putrescine formation more than BHT addition. However, no significant difference (P > 0.05) was observed in histamine formation for both the sumac extract and BHT‐added recipe. The highest tyramine concentration was observed in a control recipe (R1) prepared without any antioxidants, and the lowest was in the sumac extract‐added recipe (R3) with mean values of about 96.62 and 63.17 mg kg^?1, respectively. The control recipe (R1) was found to be the worst (P < 0.05) sample with respect to overall sensory quality and addition of either sumac extract or BHT increased (P < 0.05) the overall sensory quality of sucuk. The pH and colour attributes of sucuk were not significantly different (P > 0.05) between the addition of sumac extract and BHT. This study demonstrated that sumac extract had more effect on the quality of sucuk during the ripening period, hence it could be easily utilised in sucuk to enhance quality. Copyright © 2006 Society of Chemical Industry     

原料肉贮藏时间对牛肉发酵香肠中微生物菌相变化和蛋白质降解的影响

为探究发酵剂对鸭肉发酵香肠亚硝酸盐及生物胺的抑制作用,并为发酵香肠产品的开发及其安全性控制提供理论依据。本研究将发酵乳杆菌RA₃和植物乳杆菌RC₄以单一菌种或复配菌种接种于鸭肉发酵香肠,以自然发酵组作对照,测定香肠的亚硝酸盐、生物胺及其他理化指标。结果表明：在鸭肉发酵香肠加工贮藏过程中,各组的菌落总数及实验组生物胺含量总体上均呈现先上升后下降的趋势,各组的挥发性盐基氮（TVB-N）含量及自然组生物胺含量逐渐上升,亚硝酸盐含量则呈现下降趋势。实验组pH、TVB-N及亚硝酸盐含量始终低于自然组,在第28 d时RF组亚硝酸盐含量比自然组低1.33 mg/kg。在21~28 d,实验组的菌落总数显著低于自然组（P<0.05）。因此,接种发酵剂可以在一定程度上减少菌落总数,显著抑制亚硝酸盐和生物胺的形成（P<0.05）,可以提高香肠的安全性。     

中式发酵干香肠中乳酸菌的分离筛选、鉴定和培养

从烟台喜旺中式发酵干香肠中分离筛选出适合当地特色的、具有自然发酵香肠风味的微生物菌株,采用系统分类鉴定方法对筛选出的乳酸菌进行初步鉴定,鉴定出5种乳酸杆菌:L1为德氏乳杆菌德氏亚种,L2为德氏乳杆菌保加利亚亚种,L3为米酒乳杆菌,L4为食品乳杆菌,L5为戊糖乳杆菌。此外,采用均匀设计确定了这5种乳酸杆菌的增殖培养基的组成和最佳配比,并通过混合培养得出混合培养的最佳配比。     

Prevalence of biogenic amines during ripening of a traditional dry fermented pork sausage and its relation to the amount of sodium chloride added

The presence of biogenic amines (BA) along the processing stages and storage period of "Painho de Portalegre" and its relationship with the NaCl concentration on their levels were evaluated. Total BA concentration of current "Painho de Portalegre" dry fermented sausage increased (P<0.001) with drying/smoking processing time, attaining 655mgkg(-1) dry matter (DM) at day 6, a level about six times higher than that obtained in seasoned raw material mixtures before casing stuffing (115mgkg(-1)DM). Between day 30 and 40 in the drying/smoking house, that amount increased 20-fold (2500mgkg(-1) DM) over the initial concentration. After one month of storage under vacuum at room temperature, the concentration decreased by almost half to 1561mgkg(-1)DM. Excluding tyramine, the other BA were already present in the minced raw materials. However the sum of cadaverine, putrescine, histamine and tyramine, was well below 5mgkg(-1) proposed as BA limit for meat of high hygienic quality. Cadaverine was the most concentrated BA at the last stage of the drying/smoking (1430-1254mgkg(-1)DM, after 30 and 40 days, respectively), almost double the concentration of putrescine (882-779mgkg(-1)DM), followed by tyramine, β-phenylethylamine and spermine (376-311, 24 and 27-23mgkg(-1)DM, respectively). Variation was detected among production batches, possibly due to poor control of the processing conditions in traditional manufactures and the effects of the prevailing weather conditions. A higher salt concentration in the final product, 6% compared to 3%, led to a significant reduction in the BA level (P<0.001). This difference was particularly relevant in the early stage of the drying/smoking phase, during which the greatest microbial development mainly occurred in relation to cadaverine, β-phenylethylamine, putrescine and tyramine levels.