Effect of the addition of pancreatic lipase on the ripening of dry-fermented sausages - Part 2. Free fatty acids, short-chain fatty acids, carbonyls and sensory quality

The effect of the addition of nine different amounts (3–500 units) of pancreatic lipase on the composition of free fatty acids (FFA), short-chain fatty acids and carbonyls, as well as the sensory quality, has been studied on dry fermented sausages. The lipase produced a greater release of all fatty acids in relation to the control sausages. The greater the pancreatic lipase content, the higher the release of these fatty acids, the most important ones being myristic, palmitoleic and oleic acids. A lower release of linoleic acid was observed, probably because of its oxidative degradation. At the end of the ripening in all lipase-added batches, a clear increase of the carbonyl content was noticed in relation to conventional sausages. No consistent changes were observed in the short-chain fatty acid fraction. In the sensory evaluation, the highest significant differences (P < 0·01) between control sausages and lipase-added batches were observed when 60 and 90 lipase units were used. According to the chemical and sensory analyses, it can be concluded that the addition of 60 and 90 units to sausages seems to be useful to enhanced the flavour of these products.     

Lipolysis,proteolysis and sensory properties of ewe’s raw milk cheese (Idiazabal) made with lipase addition

In this paper, we describe the effect of the addition of pregastric lipase on the composition and sensory properties of Idiazabal cheese. Free fatty acids (FFA), partial glycerides, free amino acids (FAA), gross composition and sensory characteristics were determined at different ripening times in cheeses manufactured with three different amounts of commercial animal lipase or with lipase-containing artisanal lamb rennet paste. The addition of lipase increased the content of total FFA, particularly of short-chain FFA, and that of total partial glycerides in cheeses. Unexpectedly, lipase utilization significantly affected total FAA concentration, which decreased in cheeses elaborated with high lipase amount. In general, Val, Glu and Leu were the major FAA, and their concentrations depended, mainly, on ripening time. Lipase addition had significant influence on the sensory characteristics of the cheeses, increasing scores for most of the flavour and odour attributes of the cheese. Principal component analysis (PCA) was done including dry matter, FFA, FAA, partial glycerides and odour and flavour attributes of the cheeses. It indicated that aroma and flavour parameters of Idiazabal cheese and the content of short-chain FFA and diglycerides were highly correlated to first principal component (PC1), while texture parameters, compositional variables and FAA were correlated to the second principal component (PC2).     

Dry fermented sausages elaborated with lipase from Candida cylindracea. Comparison with traditional formulations

The addition of microbial lipase to fermented sausages was studied. A sausage with lipase from Candida cylindracea and a control sausage with starter (Lactobacillus plantarum and Staphylococcus carnosus) were produced in a pilot plant. The acidity value and the amounts of the different free fatty acids (FFA) showed a higher intensity of lipolytic activity in sausages with lipase than in sausages with starter. In sausages with lipase, the percentage of saturated FFA was greater and that of polyunsaturated FFA was lower than in sausage with starter. Mono-unsaturated FFA percentage was similar in both sausages. TBA and peroxide values indicated that the increase of FFA produced by lipase action did not increase the rancidity. A slight increase in acetic, propionic and butyric acids was observed in sausage with lipase but this was not sufficient to develop excessive acidity in the product.     

Effect of the fungal protease EPg222 on proteolysis and texture in the dry fermented sausage ‘salchichón’

Proteolytic activity of the fungal protease EPg222 and its effect on the texture of the dry fermented sausage ‘salchichón’, which has a long ripening process, was assayed. Samples with enzyme added showed a significant reduction of myofibrillar protein concentration during the ripening period, compared with a control, and proteolytic activity of the enzyme led to a higher accumulation of non‐protein and ‐amino acid nitrogen. Analysis of volatile compounds in ripened dry fermented sausages revealed that only in EPg222 batches were branched compounds derived from amino acids catabolism detected that are associated with the flavour of dry cured meat products. The texture profile analysis showed reduction in hardness, gumminess and chewiness values in treated compared with control sausages. The effect of this enzyme could be of great interest in stimulating proteolysis, in flavour development and in reducing the hardness of dry fermented sausages produced by a long ripening process. Copyright © 2004 Society of Chemical Industry     

Effect of nitrate and nitrite curing salts on the generation and oxidation of fatty acids in non-fermented sausages

 The purpose of this work was to study the effect of nitrate and nitrite curing salts on FFA generation and oxidation during an industrial process of country-style dry sausages (35/40 mm casing diameter) to determine their role in flavour development. The pH values of the sausages are around 6.0 during the dry processing. FFA liberation is two or three times greater in the samples with nitrite than in those with nitrate. However, the intensity of the oxidative phenomena during the drying process does not depend on the quantity of FFA. In the samples with nitrate more intense oxidative phenomena take place, which lead to a stronger typical dry-cured flavour than in samples with nitrite. Received: 14 July 2000 / Revised version: 15 September 2000     

Proteolysis in dry fermented sausages: The effect of selected exogenous proteases

The effect of three commercial proteases (pronase E from Streptomyces griseus, aspartyl proteinase from Aspergillus oryzae and papain) on protein breakdown and the sensory characteristics of dry fermented sausages was investigated. Water soluble, non-protein, 5% phosphotungstic acid soluble, 5% sulphosalicylic acid soluble and total volatile basic nitrogen contents increased during fermentation, stabilizing later until the end of ripening (26th day). Nitrogen values were always greater in the aspartyl proteinase added batch in comparison with the other protease added batches. Total free amino acid changes showed a similar pattern to those observed for the 5% sulphosalicylic acid soluble nitrogen. The electrophoretic studies demonstrated that proteolysis of high molecular weight myofibrillar and sarcoplasmic proteins was more prominent in protease added batches. It was especially intensive in papain one. The dominant amino acids at the end of ripening were similar in all batches. Tyramine and histamine increased throughout ripening. No significant differences in sensory properties were found between control and pronase E and papain added batches, but they were significantly different (p < 0.01) from the sausages containing aspartyl proteinase, due to an excessive softening. The effect of exogenous enzyme addition on the flavour potentiation of dry fermented sausage is discussed.     

Changes in lipid fractions and sensory properties of Idiazabal cheese induced by lipase addition

This work studied the addition of an adequate lipase to enhance lipolysis reactions and the development of piquant flavour and sharp odour in Idiazabal cheese, as an alternative to the use of lamb rennet paste. Cheeses were manufactured from bulk raw ewes' milk in 50 l vats with commercial bovine rennet and 80 lipase units of pregastric or 180 lipase units of fungal lipase and ripened for 180 days. A higher lipolytic activity was induced by lipase addition promoting strong changes in odour and flavour attributes. Both fungal and pregastric lipases increased the content of total free fatty acids (FFA), but the fungal lipase released mainly medium- and long-chain FFA. In contrast, the pregastric lipase preferably released short-chain FFA. Diglyceride (DG) content was considerably higher in cheeses made with added pregastric lipase compared with those made with fungal lipase or with no lipase. Monoglycerides (MG) were detected only in cheeses made with either lipase added, reaching comparable concentrations after ripening for 180 days. The cheeses made with pregastric lipase had the highest scores for odour and flavour intensity, and sharp and rennet odours, desirable attributes for the Idiazabal cheese made with lamb rennet paste. None of the texture attributes were significantly influenced by the concentrations of MG and DG in the cheeses made with either lipase. Thus, the pregastric lipase was more appropriate than the fungal lipase to develop a more traditionally-flavoured Idiazabal cheese.     

微生物酶与肉组织酶对干发酵香肠中游离脂肪酸的影响

以戊糖乳杆菌31-1和木糖葡萄球菌为发酵剂生产干发酵香肠,就发酵剂对干发酵香肠成熟过程中游离脂肪酸的影响进行了研究。研究结果表明,在灌肠后的1周内,脂肪的水解主要是由组织酶引起的,微生物对脂肪微弱的水解能力主要表现在干发酵香肠成熟的后期,并且发酵剂不能改变发酵香肠中游离脂肪酸的变化模式。     

CHANGES IN FREE FATTY ACID AND DIACYLGLYCEROL COMPOUNDS IN SHORT-RIPENING DRY-CURED SAUSAGE

A study on lipolysis of Southern Italy short-ripened dry-cured sausages manufactured without and with starters was carried out. Samples were submitted to microbiological and chemical analysis during drying and ripening, whereas sensory analysis was performed at the end of the ripening. The starters, addition caused the inhibition of the Enterobacteriaceae. An increase of free fatty acids (FFAs) and diacylglycerols (DAGs) during the ripening was observed. The addition of starter did not affect FFA and DAG release. The DAG profile including 1,2- and 1,3-isomers was analyzed for the first time in dry-cured sausages. Oleic, linoleic and palmitic acids, and 1,2-, 1,3-palmitinolein, 1,2- and 1,3-diolein were the most abundant compounds in FFA and DAG, respectively. A decrease in the concentration of some 1,2-DAG and an increase of 1,3-OO and 1,3-OP species during the process was observed. Finally, the addition of starter cultures slightly influenced the sensory properties of sausages.

PRACTICAL APPLICATIONS

In this work the development and application of an analytical method for the determination of free fatty acids (FFAs) and diacylglycerols (DAGs) in sausages was achieved. DAGs are intermediate products of hydrolysis and also constitute a substrate for hydrolysis reactions leading to FFA release. These latter compounds undergo a series of reactions leading to the formation of low-molecular-weight products responsible for sensory properties of dry-cured sausages. Therefore, the assessment of these lipolysis products is a useful tool for evaluating the ripening process of dry-cured sausages.     

Accelerated ripening of dry fermented sausage by addition of a Lactobacillus proteinase

Accelerated ripening of dry sausage was investigated by adding two different concentrations of proteinase isolated from Lactobacillus paracasei ssp. paracasei NCD0151 to sausage mixtures. Sausages with proteinase showed a greater pH decrease and a greater increase in lactic acid formation, water loss, protein degradation and peptide formation than control, no enzyme, sausages. Changes were most pronounced in the sausages containing 12 Ug^-1 proteinase. Addition of proteinase caused a specific increase in glutamate, serine and lysine content. Sensory evaluation after 14 days of ripening showed a significant increase in flavour intensity, maturity flavour, acidity, bitter taste and hardness in the proteinase-containing sausages. Addition of proteinase induced changes earlier in the fermentation and ripening period than in the control, thereby indicating an acceleration of maturation.     

Effect of a food-grade enzyme preparation fromAspergillus oryzae on free fatty acid release in Manchego-type cheese from ovine and bovine milk

The addition of 50 mg Flavor Age (blend of lipase, proteinases and peptidases fromAspergillus oryzae) per kilogram of mixed ovine plus bovine milk for the manufacture of Manchego-type cheese caused the release of abundant free fatty acids (FFA), especially the short-chain fatty acids (C₄ to C₁₀). The effect accentuated with ripening time, the cheeses reaching a level of FFA around 2% at 120 days. The high concentration of FFA could have partially inhibited the growth of starter culture, as can be deduced from the higher residual lactose content of enzyme-treated cheeses. The results are compared and related to those obtained in a previous study on proteolysis and flavour development by the same enzyme preparation. They suggest that in the case of Man-chego-type cheese the liberation of FFA, although necessary, could be less important for flavour enhancement than the production of free amino acids.     

Effectiveness of a Lactobacillus sakei starter culture in the reduction of biogenic amine accumulation as a function of the raw material quality

The effectiveness of an amine-negative starter culture (Lactobacillus sakei CTC494) in the reduction of biogenic amine production during the ripening of fermented sausages was examined. Four batches were manufactured in parallel: spontaneously fermented and starter-mediated sausages were manufactured from two lots of raw materials of different hygienic quality. Besides the biogenic amine contents, changes in the microbial counts, nitrogenous fractions, pH, and water content were measured at several sampling points during the ripening process. In sausages manufactured from good quality meat, the starter strain of L. sakei reduced and even inhibited biogenic amine accumulation during sausage fermentation, the end products showing extremely low biogenic amine contents (tyramine levels less than 15 mg/kg of dry matter and putrescine and cadaverine levels less than 5 mg/kg of dry matter). Nevertheless, starter-mediated sausages made from poorer-quality raw materials showed much higher amine contents (308, 223, and 36 mg/kg of dry matter of cadaverine, tyramine, and putrescine, respectively), which were only slightly lower than those of the spontaneously fermented sausages made from the same raw materials. The relatively high bacterial numbers of raw materials of poorer-hygienic quality diminished the beneficial effect of the starter strain. Therefore, the effectiveness of the starter was strongly dependent on the hygienic quality of the raw materials used.     

Biogenic amine accumulation in ripened sausages affected by the addition of sodium sulphite

The effect of two concentrations of sodium sulphite on biogenic amine accumulation during the ripening of slightly fermented sausages was examined. Three batches of sausages were manufactured: one without sulphite (control), one with 500 mg/kg and one with 1000 mg/kg of sodium sulphite. Considerable tyramine production (75–140 mg/kg dry matter [dm]) was observed in all batches. Sausages with sulphite, especially those with 500 mg/kg, accumulated higher amounts of tyramine than those without sulphite. Cadaverine was observed in the batch without sulphite (38 mg/kg dm), but its production was markedly inhibited by the presence of sulphite. A small amount of putrescine (4–12 mg/kg dm) was found during ripening and its final content was slightly higher in sausages with 1000 mg/kg of sulphite. No production of histamine, phenylethylamine or tryptamine was observed. Agmatine and spermine levels decreased during ripening, whereas spermidine levels remained constant. Although sausages with sulphite showed lower microbial counts, only cadaverine production was lower than in sausages without sulphite. In contrast, tyramine and putrescine production seemed to be stimulated by the presence of sodium sulphite.     

干发酵香肠中生物胺的产生与控制

综述了干发酵香肠中生物胺产生的条件 ,国外干发酵香肠中生物胺的含量 ,与生物胺积累有关的微生物以及影响生物胺产生的理化因素 ,并提出了控制干发酵香肠中生物胺积累的措施。     

Effects of Freeze‐Dried Vegetable Products on the Technological Process and the Quality of Dry Fermented Sausages

The aim of this study was to compare the chemical composition of freeze‐dried vegetable powders: celery, celery juice, parsnip and leek. The effect of different freeze‐dried vegetables onto the ripening process and the properties of dry fermented sausages was also evaluated. Vegetable products significantly (p < 0.05) differed in their chemical composition: celery products contained higher amounts of nitrates, total phenolic compounds and lower amounts of sucrose, parsnip had higher concentration of proteins, leek was rich in fat. The analysis of pH, water activity, lactic acid bacteria, coagulase‐positive staphylococci and coliforms content showed that the incorporation of freeze‐dried vegetables had no negative effect on the fermentation and ripening process of dry fermented sausages. In addition, the color parameters for sausages with the added lyophilised celery products were considerable (p < 0.05) more stable during these processes. At the end of the ripening process the sausages made with lyophilised celery juice were characterised by higher lightness and lower hardness than those made with the addition of other vegetable products and control. Freeze‐dried celery, celery juice, parsnip and leek have some potential for the usage as a functional ingredient or as a source for indirect addition of nitrate in the production of fermented sausages.     

Effect of wine addition on microbiological characteristics,volatile molecule profiles and biogenic amine contents in fermented sausages

The aim was to evaluate the effect of wine addition during manufacturing of dry fermented sausages, in terms of safety aspects (biogenic amine accumulation), aroma profile and sensory characteristics. Three batches of salami were produced: without wine addition and with 7.5% or 15% (v/w) of white wine. The fermented sausages showed characteristics that can increase product diversification. Some of the sensory features (i.e. increased salty perception) can represent an important strategy because of the trend to reduce salt intake for health reasons. The presence of wine immediately reduced the pH and is a source of ethanol, which can have an inhibitory effect against undesirable microflora. The microbiological results observed regarding Enterobacteriaceae and enterococci were encouraging. The addition of wine did not negatively affect the ripening time or increase the presence of biogenic amines. The samples containing wine showed reduced concentrations of putrescine.     

干发酵香肠中的生物胺

综述干发酵香肠中生物胺产生的条件,国外干发酵香肠中常见生物胺的种类及含量,与生物胺积累有关的微生物以及影响生物胺产生的理化因素,并提出了控制干发酵香肠中生物胺积累的措施。     

Characterization of the free fatty acids profile of Pategrás cheese during ripening

This work compares the free fatty acids (FFA) profiles of Pategrás cheeses manufactured on the pilot scale, with and without the addition of probiotics. Total and FFA in milks and cheeses, respectively, were similar, indicating a nonselective release during ripening. Lipolysis was lo for control cheeses, but somewhat higher for those made in summer, probably because of an elevated psychrotrophic bacterial development. Probiotic bacteria remained highly viable during ripening and had an influence on FFA profiles. A simple sensory profiling of the cheeses showed no differences in flavour and taste and little evidence of treatment effects was found using univariate analysis. Nevertheless, multivariate analysis showed clear differences between probiotic and control products.     

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