Colour parameters of Turkish-type fermented sausage during fermentation and ripening

Colour parameters of Turkish-type fermented sausage during fermentation and ripening were evaluated. CIE x y, L^* a^* b^*, C^* h°, pigment nitrosation (NI) and pigment discoloration (RSI) were measured. Sausage processing had four stages consisting of first and second fermentation steps and then two consecutive ripening steps. Variations of colour parameters with processing indicated that Turkish-type fermented sausage processing might be divided into two well defined phases from the colour point of view. Optimum colour was obtained at the end of the first ripening step.     

The change in meat pigments in sausage making processes

The colour of cured meat and sausages depends essentially on the chemical modifications of the natural pigments of animal muscle. This paper deals with the influence of processing on the pigments and the control of their transformation by studying the refletion spectra of the surface of the samples. It is demonstrated that better curing conditions may be obtained by accurate control of the chemical modifications of pigments during the different stages of processing: curing, smoking, drying, etc. The keeping qualities of non-heated cured meat products (e.g., fermented sausages) depend essentially on the efficiency of the nitrosation process. Incomplete nitrosation of the porphyric pigments increases the sensitivity to discoloration by a Fe²⁺ → Fe³⁺ oxidation of the residual native myoglobin.     

Optimization of instrumental colour analysis in dry-cured ham

Colour of dry cured ham was measured by instrumental techniques in order to determine the optimum measurement index. Five different colour systems were used: CIE L(?)a(?)b(?), Hunter Lab, CIE L(?)u(?)v(?), xyY and XYZ, each with illuminants D65, C and A, and with both 10 and 2° observer angles. Measurements were taken in both Semimembranosus (SM) and Biceps femoris (BF) muscles. Hunter Lab system with illuminant A gave the most reproducible results within muscles for the three colour parameters evaluated. A further comparison of results obtained with 10 and 2° observer angles of Hunter Lab with illuminant A showed there were no significant differences between the angles. Significant differences between results from SM and BF muscles were found in all the hams, the BF always showing higher values than SM for every colour parameter.     

Characterization of changes in psychometric colour attributes of comminuted porcine lean meat during processing

Changes in colour during the processing of a comminuted porcine lean meat system were characterized using the psychometric colour attributes lightness L (?)) hue (h (?))and chroma (C (?)). The effects of processing temperature, nitrite and air pressure during comminution were examined. The pattern of changes as a function of processing time for L (?) and C (?), but not for h (?), showed clear dependence on processing temperature (15, 30, 40, 50 and 60°C). For C (?) this dependence was much more complex than foor L (?). Nitrite dramatically affected the pattern of change in h (?) and C (?), but much less so changes in L (?). Varying the air pressure during comminution did not induce shifts in patterns of changes of the three colour attributes. However, it did have a marked effect on the absolute values and the extent of changes in L (?) and, to a much lesser extent, in h (?) and C (?). The findings of this study furnish the basis for a possible usage of the psychometric colour attributes as parameters for a quantitative kinetic analysis and modelling of the effect of processing factors during the production of comminuted meats.     

An Improved Method for Preparation of Nitric Oxide Myoglobin

We developed an improved method for preparation of bovine nitric oxide myoglobin using the following starting materials: 0.1 mM purified metmyoglobin; 0.1 mM (7 ppm) sodium nitrite; and 1.76 mM (350 ppm) sodium ascorbate. The method requires complete deoxygenation of the reacting system. NOMb prepared in this manner is a source of cured meat pigment which contains a minimum of impurities, since the nitrite reacts quantitatively with the myoglobin in this method.     

Changes in several constituents during the ripening of 'Chorizo' - A spanish dry sausage

'Chorizo', a dry fermented sausage marketed in Spain, is traditionally prepared without curing agents or sugars. In order to establish the fermentation process batches A (with added sugars) and B (traditional process) were prepared. pH, carbohydrate disappearance, cured meat pigment formation, free fatty acids (FFA), non-protein nitrogen (NPN) and NH(4)(+) were determined through 100 days of ripening. In batch A, cured meat pigment formation, pH decrease and NPN evolution were greater than in batch B, whereas FFA and NH(4)(+) were similar. Garlic and Spanish paprika added to the mixture introduced significant amounts of fermentable carbohydrates (0·68%) and approximately 16 ppm NO(3)(-).     

Microbiological and biochemical changes during ripening of salchichón,a Spanish dry cured sausage

Development of the microflora and changes in the lipid and protein fractions during the ripening of salchichón, a kind of Spanish dry cured sausage, were studied. A commercial mixture of Pediococcus pentosaceus andMicrococcus varians was used as starter culture. Total aerobic bacteria, lactic acid bacteria, Micrococcaeae, Staphylococcus aureus, Entero-bacteriaceae , sulphite reducer Clostridium , yeasts and moulds were determined. The sarcoplasmic and myofibrillar solubility, denaturation and proteolysis index, parameters related to fat stability and the free fatty acid composition were analysed throughout the curing process: after mincing, after the fermentation stage, after the 2nd week of drying and in the final product (4th week of drying). The major changes in the characteristics of salchichón took place during the fermentation stage. This was due to proteolysis and lipolysis phenomena derived from high counts of lactic acid bacteria and Micrococcaeae in this stage. These changes were shown in the increase of the total free amino acid content, the peroxide index and the carbonyl compound content, and in the decrease of the protein solubility and the percentage of polyunsaturated free fatty acids, thus achieving the organoleptic characteristics of the final product.     

Colour of beef heated to different temperatures as related to meat ageing

The effects of ageing (10-12 days at +5°C), thermal treatment (internal temperature, T(i): 45, 60, 75°C) and oxygenation on the colour and some colour related physical and biochemical parameters of beef longissimus dorsi (LD) muscle were studied. The colour components (L(?), a(?) and b(?) values) for the raw and heated LD, both before and after ageing and oxygenation, were instrumentally and sensorily evaluated. Ageing influenced colour components (except b(?) value), specific activity of cytochrome c oxidase (SACCO) and amount of oxygen consumed (AOC). An increase in internal temperature was usually accompanied by a lower SACCO, AOC and total native muscle pigment concentration, as well as a change in all colour parameters. Oxygenation of the raw and heated slices (except T(i)=75°C) led to a less of black colour and a higher of red colour, a(?) and b(?) values.     

Effect of dietary vitamin E supplementation on the shelf life of cured pork sausage

This study examined the shelf life of cured sausage under different packaging conditions from vitamin E supplemented pigs. One group (n=6) of crossbred pigs received a normal fattening diet containing 20 ppm α-tocopherol for 39 days before slaughter. Another group was fed a diet containing 410 ppm α-tocopherol during the same period. After slaughter, cured sausages were produced, packaged under three different atmospheric conditions, ripened for 4 weeks and then stored for 8 weeks (9?°C; 200 lux). The α-tocopherol content was recorded in the fat, liver, muscles and the sausage. TBARS, L*, a*, b* values and antioxidative capacity were evaluated in the sausage during storage. The results showed a transfer of vitamin E into tissues and sausage but no detectable effect on TBARS and colour stability. However, antioxidative effects of vitamin E were seen by provocation. Probably the effect of vitamin E in the sausage was masked by nitrite in the curing salt. The oxygen content of the packs had an influence on TBARS and colour stability.     

Veal colour assessment with three wavelengths

A method to derive reflectance spectra and colour coordinates of meat by measurement of reflectance at only three wavelengths, 480, 570 and 620 nm has been developed, by treating the spectra of a meat sample as a linear combination of the spectra of the three major myoglobin derivatives (reduced myoglobin, oxymyoglobin and metmyoglobin). Applied to 300 samples of Semitendinosus and Longissimus dorsi veal muscles at different times post mortem (24 h to 9 d), colour differences ΔE (?) between the derived spectra and the real ones were about 1.5 units. The total pigment content, with high correlation with the extraction method (P < 0.02), and the relative proportions of the derivatives can also be estimated.     

Colour changes during manufacture of Galician chorizo sausage

 Galician chorizo sausage is a smoked-meat product containing chilli pepper. This study investigated changes in its colour (CIE colour coordinates L*, a* and b*, together with redness index, hue, chroma and perceived colour) during the curing process. Samples were obtained from three manufacturers (A, B and C) whose smoking and curing procedures differ markedly. Most of the colour measurement showed clear changes during curing. All measurement except external L* varied significantly among samples obtained from the different manufacturers. Pairwise comparisons indicated that in most cases there were significant differences between samples from manufacturer A (who smokes the product for only 6 h) and manufacturers B and C (who smoke the product for a longer period), but not between samples from manufacturers B and C. The pH, water activity and moisture content were also monitored; again, these variables differed significantly between A and B and between A and C, but not between B and C. Received: 8 October 1997 / Revised version: 19 January 1998     

Colour changes during manufacture of Galician chorizo sausage

 Galician chorizo sausage is a smoked-meat product containing chilli pepper. This study investigated changes in its colour (CIE colour coordinates L*, a* and b*, together with redness index, hue, chroma and perceived colour) during the curing process. Samples were obtained from three manufacturers (A, B and C) whose smoking and curing procedures differ markedly. Most of the colour measurement showed clear changes during curing. All measurement except external L* varied significantly among samples obtained from the different manufacturers. Pairwise comparisons indicated that in most cases there were significant differences between samples from manufacturer A (who smokes the product for only 6 h) and manufacturers B and C (who smoke the product for a longer period), but not between samples from manufacturers B and C. The pH, water activity and moisture content were also monitored; again, these variables differed significantly between A and B and between A and C, but not between B and C. Received: 8 October 1997 / Revised version: 19 January 1998     

Physicochemical characteristics of Spanish-type dry-cured sausage

The colour and physicochemical parameters of Spanish-type dry-cured sausage during fermentation and ripening were evaluated. The CIE L*, a*, b* and pH, moisture content, lactic acid concentration and residual nitrite level were measured in two different zones (centre and peryphery). Sausage processing had two stages, fermentation and ripening. Lightness (L*) was the only colour parameter whose development (during the ripening stage) was dependent on the zone studied, in this case becoming lighter in the center zone. Redness (a*) increased during the fermentation stage and decreased during ripening, while the yellowness (b*) decreased throughout the process. The development of pH, lactic acid and residual nitrite levels were non related to the zone studied during both the fermentation and ripening stage.     

Technological suitability of mutton for meat cured products

A comparative study on the technological suitability of mutton and pork for meat cured products was carried out. One type of cured dry sausages was made of mutton and the other of pork, using the same formulation and technological conditions. Thus, the evolution of physico-chemical and microbiological parameters, as well as colour and texture were measured at three different stages of the process: after mincing, after fermentation and after drying. The sensory parameters were assessed in the final product. Both mutton and pork had a similar technological aptitude during processing of cured dry sausages, with a similar evolution of the pH value, a_w and Lactobacilli counts. The main differences between both types of sausage were observed in texture, colour and in the organoleptic characteristics, having mutton sausages greater cohesivity and more stable and redder colour than pork sausages. Besides, mutton sausages showed an aroma, flavour and texture that were not desirable for the panellists.     

Effect of nitrate and nitrite curing salts on lipolysis in dry sausages produced using a rapid fermentation process

 The effect of nitrite and nitrate curing salts on lipolysis in a typical non-smoked Spanish sausage (salchichón), manufactured using a rapid dry fermentation process, was studied. From the results obtained, one could deduce that nitrite and nitrate per se do not affect the endogenous hydrolysis of the lipids during the rapid fermentation process used to produce dry sausage. Polyunsaturated fatty acids (PUFA) are liberated in greater quantities than monounsaturated (MUFA) and saturated (SFA) ones, which suggests that they are derived mainly from phospholipids. The samples that contained nitrate curing salts contained more free fatty acids (FFA) (548 mg/100 g) than those that contained nitrite curing salts (478 mg/100 g) at the end of the fermentation step, as a consequence of having undergone a preripening stage, during which significant amounts of FFA are formed. However, at the end of the ripening process, although there is a significant increase of FFA levels in all the sausages, no significant differences between samples with nitrite and those with nitrate could be found. This result could have occurred if the oxidative effects of the samples with nitrate balanced the antioxidative properties of nitrite, such that, through different processes, similar concentrations of FFA are obtained at the end of ripening. Phospholipids (PL) and free fatty acids (FFA) are the lipid fractions that undergo the most important changes during ripening. PL are moderately degraded during the drying process, probably due to the combined effects of the drying temperature (10°C) and the presence of starters. However, this degradation does not differ significantly between the samples that contain nitrite and and those that contain nitrate in each control. Received: 23 July 1997 / Revised version: 8 October 1997     

Effect of nitrate and nitrite curing salts on lipolysis in dry sausages produced using a rapid fermentation process

 The effect of nitrite and nitrate curing salts on lipolysis in a typical non-smoked Spanish sausage (salchichón), manufactured using a rapid dry fermentation process, was studied. From the results obtained, one could deduce that nitrite and nitrate per se do not affect the endogenous hydrolysis of the lipids during the rapid fermentation process used to produce dry sausage. Polyunsaturated fatty acids (PUFA) are liberated in greater quantities than monounsaturated (MUFA) and saturated (SFA) ones, which suggests that they are derived mainly from phospholipids. The samples that contained nitrate curing salts contained more free fatty acids (FFA) (548 mg/100 g) than those that contained nitrite curing salts (478 mg/100 g) at the end of the fermentation step, as a consequence of having undergone a preripening stage, during which significant amounts of FFA are formed. However, at the end of the ripening process, although there is a significant increase of FFA levels in all the sausages, no significant differences between samples with nitrite and those with nitrate could be found. This result could have occurred if the oxidative effects of the samples with nitrate balanced the antioxidative properties of nitrite, such that, through different processes, similar concentrations of FFA are obtained at the end of ripening. Phospholipids (PL) and free fatty acids (FFA) are the lipid fractions that undergo the most important changes during ripening. PL are moderately degraded during the drying process, probably due to the combined effects of the drying temperature (10°C) and the presence of starters. However, this degradation does not differ significantly between the samples that contain nitrite and and those that contain nitrate in each control. Received: 23 July 1997 / Revised version: 8 October 1997     

引进烤烟品种KRK26烘烤特性研究

为摸清津巴布韦特色烤烟品种KRK26 烘烤特性,以烤烟品种云烟97 为对照,研究了暗箱条件下和烘烤过程中KRK26上部烟叶变黄和失水变化规律及烤后烟叶经济性状。结果表明,暗箱条件下KRK26 变黄速度快,失水速度稍慢,易发生褐变;烘烤过程中KRK26 叶绿素降解速度快且彻底,类胡萝卜素降解相对较慢,类叶比大,变黄速度快,易变黄,变黄特性好,但也易于变褐,不耐烤;烘烤变黄前期和干筋期失水速度快,变黄后期和定色期失水相对稍慢,失水特性中等;KRK26失水速度相对落后于变黄速度,二者协调性稍差,烤后烟叶青杂烟比例较高,易烤性和耐烤性均略差。变黄期采用低温变黄的方法,变黄前期降低干湿球差控制烟叶失水,变黄后期和定色前期增加排湿力度,可调节烟叶失水和变黄协调性,有利于提高KRK26 烘烤质量。     

不同烘烤条件下烟叶色素降解规律的研究

以烤烟品种ＮＣ８９为试材，研究了不同烘烤条件下烟叶的变黄指数和叶片色素含量的变化。结果表明，随着烟叶变黄时间的延长，烟叶的变黄指数逐渐增大，达到最大值后则趋于稳定；烟叶中叶绿素降解速度呈现出变黄前期降解缓慢，中期加快，后期又变慢的规律性。不同处理相比，以三段式烘烤工艺烟叶中的叶绿素降解最为充分，烤后烟叶品质最好。     

发酵香肠干制过程中理化及微生物指标的变化

采用传统中式方法制作猪肉香肠,定期检测发酵香肠干制过程中理化及微生物指标的变化。通过对水分、pH值、水分活度、酸值和挥发性盐基总氮等理化指标以及细菌总数的测定,确定发酵香肠干制过程中各项指标变化范围,并对比了发酵组和对照组各项指标的差异,为发酵香肠干制提供理论依据。     

Lean colour of green and matured Parma hams: Comparative evaluation and technological relevance of sensory and objective data

Research has been conducted on the relationship between sensory evaluation and objective measurement of pork colour. The study also investigated the relationship between the colour of fresh meat and the colour of matured hams. Sensory evaluation was carried out at 24 h post mortem on the freshly cut surfaces of green hams trimmed for Parma ham production. Objective measurements were performed at the same time on Semimembranosus and Biceps femoris muscles with a Minolta Chromameter Reflectance II CR200/08. Cold carcass weight, lean content, trimmed ham weight, 45 min and 24 h post mortem pH of Semimembranosus muscle were also recorded. The hams were processed according to Parma ham technology. Weight losses at standard processing times were collected. At the end of processing a sample of about one-third of the hams was evaluated for internal lean colour and lean firmness both by sensory panel and objective measurements. Proximate composition was also determined. The results showed highly significant relationships between colour sensory scores and the coordinates L (?), b (?) and hue of the C.I.E. L (?)a (?)b (?) colour system. Among the other parameters measured on fresh meat only 24 h pH was related at a very significant level with sensory and objective colour values. Correlation coefficients were generally higher for Semimembranosus than Biceps femoris. Matured ham colour was linked with fresh meat sensory judgements, L (?), hue and a (?) values. The relationship, though, was not sufficiently strong for use in predicting the colour of matured hams from green ham characteristics. Processing appears to have a positive effect on the colour of pale meat. Weight losses were mainly linked with lean meat content; other quality attributes being less important. Lean firmness of matured hams was related to the colour and pH of the fresh meat.