Effect of brine thawing/salting for time reduction in Spanish dry-cured ham manufacturing on proteolysis and lipolysis during salting and post-salting periods

The simultaneous brine thawing/salting operation has been proposed as an effective alternative for the accelerated processing of frozen cured hams. The aim of the present study was to study the effect of this new technology on the lipolytic and proteolytic enzymes responsible for the generation of flavour precursors during the salting and post-salting stages of the manufacturing of Spanish dry-cured ham. The effect of the frozen and thawed process produced a higher proteolytic and lipolytic activity than in the fresh traditional salted hams (FPS) that was detected by a higher concentration in free amino acids and free fatty acids. On the other hand, the brine thawed/salted treatments, at atmospheric pressure (BTS) and with vacuum impregnation (BTS-TP), produced an acceleration of the myofibrillar degradation that occurred in the BTS and BTS-TP hams in comparison to FPS. However, the lipolysis was affected by the frozen treatment but not by the brine thawed treatments, as few differences in free fatty acids and lipase activity were detected among the frozen and brine thawed hams at the end of post-salting stage.     

Effect of brine thawing/salting on endogenous enzyme activity and sensory quality of Iberian dry-cured ham

Simultaneous brine thawing/salting process was applied as an alternative to traditional pile salting process using 51 frozen Iberian hams. The effect of this type of salting process on endogenous enzyme activity and sensory quality of Iberian dry-cured hams was analysed. The frozen hams were simultaneously thawed and salted with saturated brine, with and without vacuum pulses, and were compared to hams thawed under refrigeration and traditionally salted. The peptidase and lipase activities were measured at the end of salting and post-salting stages. The activity of cathepsin B+L was reduced in the two brine salted batches while few differences among batches were observed for the other peptidases. Several lipase activities were significantly reduced in the two brine salted batches. The brine thawed processing affected the free fatty acid content at the different stages although the differences were more appreciated at the beginning of the process and no differences were observed at the end. The long ripening time makes these differences negligible and the consumer did not appreciate any differences between the sensory quality of Iberian brine/thawed hams and traditional Iberian thawed pile salted hams.     

Use of simultaneous brine thawing/salting in dry-cured Iberian ham production

The study of simultaneous brine thawing/salting as an alternative to the traditional stages in Iberian dry-cured ham processing was carried out employing 75 pre-cured frozen hams from Iberian pigs. The frozen hams were simultaneously thawed and salted with saturated brine for periods of 3, 5, and 7 days with and without the application of a vacuum pulse in order to reach the same salt concentration as the traditional procedure. The post-salting behaviour of the brine/thawed hams was also studied. The results obtained indicated that simultaneous thawing and salting would considerably reduce the time needed to reach the same salt concentration as with the traditional procedure (77% and 63% reduction with and without vacuum pulse, respectively). This also implied lower dehydration, so an increase in the post-salting time or in the weight lost during this stage is required.     

Accelerated processing of dry-cured ham. Part I. Viability of the use of brine thawing/salting operation

In a previous study, the brine thawing/salting operation using frozen hams as raw material was proposed in order to obtain accelerated processing of dry-cured hams. The time needed to reach the same NaCl concentration on a dry weight basis and the same NaCl concentration in the ham liquid phase for the deeper areas at the end of the post-salting stage were determined.

The aim of this work was to study the influence of the brine thawing/salting operation on the whole dry-cured ham manufacturing process, using the traditional thawing and salting methods as control.

The obtained results indicate that although a strong reduction in the thawing, salting and post-salting stages is obtained by using brine thawing/salting, the time needed in the dry-curing and maturing phases increases compared to those traditionally processed, probably due to the absence of pile salting and thus the reduction in the thickness of the ham piece as a consequence of the ham pressing. From the composition and microbiological point of view, no significant differences were observed among the hams processed by the different treatments.     

Study of salting and post-salting stages of fresh and thawed Iberian hams

Fresh raw material has been traditionally used to obtain dry-cured Iberian ham, although the use of thawed raw material is increasing. This type of raw material has been previously studied for dry-cured production employing White pigs, where the salting time has been reduced to reach similar NaCl concentrations. The aim of this work was the analysis of salting and post-salting stages of Iberian hams, employing fresh or thawed raw materials. The results showed that fresh Iberian hams had higher salt concentrations than thawed Iberian hams for the salting time ratio used, a ratio established to reduce the freezing/thawing effect that was previously observed working with White ham. This fact shows that the Iberian raw material in dry-cured ham manufacturing is less affected, by the freezing/thawing process than the White raw material.     

Replacement of pile salting by simultaneous brine thawing-salting in Spanish cured ham manufacturing

Salting, is one of the fundamental operations in Spanish cured ham manufacturing, and is basic in order to preserve the product throughout its processing and storage. Pile salting is the method traditionally employed to accomplish this step. The use of frozen raw material has become quite frequent in the industry, and it implies a preliminary thawing step in a cold chamber. The aim of this study is the analysis of the first step in ham production (salting) and the influence of simultaneous brine thawing/salting and vacuum impregnation in the salting stage of Spanish cured ham. The results indicated a reduction in the salting time when using the brine thawing/salting method, which was performed together with vacuum impregnation. Further studies need to be done in order to fully understand the influence of these new salting methods on the following manufacturing steps and the final quality characteristics.     

Accelerated processing of dry-cured ham. Part 2. Influence of brine thawing/salting operation on proteolysis and sensory acceptability

In a previous study, the brine thawing/salting operation using frozen hams as raw material was studied as a valid alternative for the accelerated processing of dry-cured hams. But no information was available on how this treatment could affect some important biochemical mechanisms and the sensory quality of hams. The aim of this work was to study the influence of the simultaneous brine thawing/salting operation on proteolysis and sensory acceptability of the produced dry-cured hams. The results confirm that dry-cured hams can be produced by using brine thawing/salting with a substantial reduction in the thawing and salting time needed. This accelerated process resulted in similar or even better sensory preferences than hams produced through the traditional method. However, the preference of consumers based on the appearance was lower for most of the hams than when using the traditional method, probably due to a wider slice section of the brined hams that can be corrected by adequate pressure during the salting. Thus, this treatment can be used without affecting the quality of dry-cured hams.     

Effect of prefreezing hams on endogenous enzyme activity during the processing of Iberian dry-cured hams

The use of frozen/thawed raw material in the processing of Iberian dry-cured ham has been studied to determine its effect on the sensory quality of the final product. The proteolysis and lipolysis processes were measured by the proteolytic and lipolytic enzyme activities and free amino acids and free fatty acids. The thawed Iberian hams had lower salt contents throughout the process. The use of thawing raw material did not affect the proteolytic enzymes, cathepsins, aminopeptidases and dipeptidylpeptidases, only the activity of dipeptidylpeptidase III was reduced due to thawing. Moreover, there were no differences in the content of free amino acids between fresh and thawed hams during the whole process. However, the use of thawing hams affected the lipolytic activity. The activity of phospholipase and neutral lipase were significantly higher in the thawed hams and also the content of free fatty acids, at all the stages analyzed. Consumer sensory analysis showed thawed Iberian hams had the lowest hardness, probably due to an intense proteolysis. The acceptability of the Iberian hams was similar between fresh and thawed hams.     

The effect of using PSE meat in the manufacture of dry-cured ham

 Drying, salting, protein changes, colour and the sensory quality were studied in dry-cured ham manufactured from refrigerated and frozen/thawed raw pale, soft and exudative (PSE) meat. The results obtained showed that the use of PSE meat increases the level of drying, salting and proteolysis of the dry-cured ham, although it does not significantly affect the sensory quality. Freezing and thawing of the raw material accentuates the proteolytic and exudative nature of the meat during the curing process, and as a result the salting and drying levels increase to such an extent that the PSE effect in these hams is practically undetectable. Received: 6 June 1997 / Revised version: 17 July 1997     

Hot curing Wiltshire bacon

A process combining multi-needle injection and dry salting of whole baconsides before they have been completely chilled can produce acceptable Wiltshire bacon in only 5 days from slaughter. Eating quality and storage stability of sliced and vacuum packed, hot cured bacon were similar to those of dry salted bacon made from conventionally chilled sides. The yields of hot cured and cold cured raw bacon were similar, but cooking yields of hams were over 3.0% higher with hot curing.
A continuous hot curing process from slaughter, through carcass preparation, multi-needle brine injection, dry salting to chilling could simplify Wiltshire bacon processing. The concept could be particularly useful to a processor lacking the specialized facilities for traditional immersion curing.     

腊肉真空腌制工艺条件的优化

以猪脊背肉为原料,研究了真空腌制工艺中真空压力、腌制液浓度、原料质量和真空腌制时间4个因素对其真空腌制速率的影响。单因素实验及正交实验结果表明,腊肉真空腌制的最佳条件为:真空压力86kPa、腌制液浓度25%、原料质量125g、真空腌制时间5h,方差分析结果显示该最佳工艺与其他各组工艺存在着极显著差异。     

Influence of low-sodium mixtures of salts on the post-salting stage of dry-cured ham process

The reduction of added sodium chloride in dry-cured ham has been proposed to decrease the amount of sodium in the diet. The effect of substituting sodium chloride by potassium chloride, calcium chloride and magnesium chloride in some physicochemical characteristics of dry-cured ham throughout the post-salting stage was evaluated. The partial replacement of NaCl had significant effects on salt content at the end of the post-salting stage in the traditional process and this significantly affected a_w. The results showed that lower sodium hams, salted with a combination of NaCl and KCl, needed a maximum of 16 days more (32% increase) of post-salting than hams salted with 100% NaCl, while hams salted with a combination of NaCl, KCl, CaCl₂ and MgCl₂ needed a maximum of 26 days more (52% increase).     

Recent advances in cured raw ham manufacture

Cured raw hams are a valuable and popular group of meat products. The consumption and international trade have increased during the last years, therefore new technologies to accelerate the production process and to increase product quality and safety are needed. In the current review, an overview of European protected cured raw hams is presented. Furthermore, traditional methods for cured raw ham production together with recent advantages in the techniques for pretreatment (trimming, blade tenderization, and freeze-thawing), curing/salting (tumbling, vacuum impregnation, pulsed pressure, ultrasound, pulsed electric fields, simultaneous thawing/salting), drying/ripening (Quick-Dry-Slice-process, oil drop application, high temperature short time process) and postprocessing (vacuum and modified atmosphere packaging, high hydrostatic pressure, high pressure carbon dioxide, high pressure carbon dioxide with ultrasound) are described. Moreover, application techniques and effects of protective cultures and starter cultures, such as molds, yeasts, coagulase-negative staphylococci and lactic acid bacteria, on cured raw ham quality and safety are reviewed.     

Frozen herring as raw material for spice‐salting

One batch of herring (Clupea harengus) was spice‐salted fresh and as thawed after 32 days of frozen storage at −24 °C. After salting, samples of both groups were sent to participating laboratories in Iceland, Denmark, Norway, Germany and England. The herring was kept at 5 ± 1 °C and sampled three times during a 26 week storage period. The development of taste and texture characteristics (determined by sensory evaluation and instrumental texture measurements), formation of low‐molecular‐weight nitrogen compounds and changes in proteolytic activity were followed in both groups. The sensory evaluation results showed that thawed salted herring ripened in a similar manner to herring salted fresh, but at a faster rate. Instrumental texture analysis showed a faster rate of tenderising in thawed salted herring. Proteolytic activity measured as general activity and with specific synthetic substrates was higher in the thawed salted herring. The formation of trichloroacetic acid‐soluble nitrogen and free amino acids was faster in the previously frozen herring. The results show an accelerated but similar rate of ripening in thawed spice‐salted herring in comparison with fresh salted herring. © 2000 Society of Chemical Industry     

Free fatty acid content of Manchego-type cheese salted by brine vacuum impregnation

A new salting method based on the brine vacuum impregnation of porous products was tested in Manchego-type cheese in order to assess its effect on cheese lipolysis during ripening. This new salting method would allow a faster salt diffusion and a more homogeneous initial salt distribution, and would reduce the disposal of brine. Salt-in-moisture content was evaluated in three different cheese zones during a 90-day ripening period in order to monitor salt penetration in the cheese. Lipolysis was evaluated by means of gas chromatography of individual free fatty acids in the medium and internal zones of both cheeses salted by the conventional and the new salting procedures. Free fatty acid concentration regularly increased during ripening. Short-chain free fatty acid content was higher in the internal zone of conventionally salted cheeses than in the internal and medium zones of vacuum impregnated cheeses from the first month after manufacturing, probably due to the low initial salt concentration achieved in the inner zone of conventionally salted cheeses, which can enhance both bacterial and indigenous lipase activity. Panelists considered that conventionally salted cheeses presented a more intense aroma than vacuum impregnated cheeses, though no differences in global flavor intensity were observed.     

Quantification and kinetics of the residual brine generation during ham and shoulder pile salting

Salting is one of the most important stages of the traditional process of cured ham manufacturing. During pile salting a saturated brine is formed and drips through the orifices located at the bottom of the salting containers.

The objective of the present work was to quantify the released brine in the ham manufacturing industry in Spain and to relate the brine generation with the salt gained by hams in the process.

The total released brine during ham and shoulder salting in Spain was determined theoretically and from the experimental values obtained from the industry (around 38,000 metric tons in 2002). In addition to that, an easy method for the estimation of the NaCl gained by hams and shoulders was developed by using the measurements of the released brine (the estimated NaCl gained differed 3.5% from the experimental data).     

Meat and storage effects on processing characteristics of beef roasts

Two experiments were done to determine the effect of storage conditions and meat cut on the processing characteristics of beef roasts. The first experiment examined the effect of storage condition (fresh/frozen), cap on/off, thawing regime and holding time post thawing on purge, brine uptake, cook yield and colour of raw and cooked roasts. The second experiment examined the effect of meat cut (insides/flats) and chilled storage for up to 8 weeks on processing characteristics of roast beef. Purge was greater for insides stored frozen without cap and air thawed. Frozen thawed cuts had increased brine retention after injection, after tumbling and after cooking. Flats had less purge and higher cook yields when manufactured into roast beef. Raw and cooked colour was not significantly affected by most factors investigated. Raw meat was more red than meat that had been frozen.     

Comparison of physicochemical and sensory changes in fresh and frozen herring (Clupea harrengus L.) during marinating

BACKGROUND: The influence of freezing on the changes during ripening is better described for salted fish than marinades. Therefore in the present study the effect of preliminary freezing of raw material on the ripening of carcasses and fillets marinated during 18 days at a temperature of 10 °C, in brine with 6% salt and 5% acetic acid was examined. RESULTS: In both cases the marinating of thawed frozen material resulted in larger mass losses and decrease of the value of meat colour parameters. The semi‐marinades from raw herring were characterised by higher values of total estimation based on sensory analysis. The statistical analysis showed weak correlation between the discriminants of sensory assessment and the studied physicochemical parameters of semi‐marinades. CONCLUSIONS: These results suggest that the semi‐marinades from raw fish are characterised by higher sensory quality, better colour parameters and higher yield than those from frozen thawed fish. Copyright © 2010 Society of Chemical Industry     

Methods for phosphate addition in heavy salted cod (Gadus morhua L.)

Headed and gutted fresh or frozen and thawed cod (Gadus morhua L.) from the same net catch were hand filleted post rigor before carrying out small-scale salting trials. Fillets were heavy salted using three different methods introducing phosphate during injection, brining, or during pickle salting. For all salting methods, treatment with 0, 4.5, 9 or 18 g/L of the pyro and tri polyphosphate blend Carnal 2110 was carried out. Quality and chemical parameters were analyzed after 5 weeks and 6 ± 1 months of chilled storage of heavy salted fillets.     

Pre-cure freezing affects proteolysis in dry-cured hams

Several parameters (sodium chloride, moisture, intramuscular fat, total nitrogen, non-protein nitrogen, white precipitates, free tyrosine, L* a* b* values and acceptability) related with proteolysis during the curing were compared in dry-cured hams manufactured from refrigerated and frozen/thawed raw material. Pre-cure freezing increased the proteolysis levels significantly (p<0.05) in the zones of the ham where water losses and absorption of salt is slowest. Frozen hams present a high incidence of white precipitates, formed mainly by tyrosine crystals. The colour and acceptability scores are similar in frozen and refrigerated hams. The previous freezing and thawing process accentuates the water losses, salt absorption and proteolysis of the cured meat, although it does not significantly affect the sensory quality of the dry-cured ham.