基于SPME-GC-MS、电子鼻、电子舌技术联用对不同替代盐干腌火腿风味成分表征

研究不同食盐配方对干腌发酵火腿理化特性、细菌菌群变化、挥发性风味物质、风味特征的影响.以4种盐配方发酵火腿,分别为对照组(CK:100％氯化钠)、替代组1(K:30％乳酸钾+70％氯化钠)、替代组2(K+L:18％乳酸钾+12％赖氨酸+70％氯化钠)、替代组3(K+J:18％乳酸钾+12％精氨酸+70％氯化钠).结果表...     

Computed tomography for quantitative determination of sodium chloride in ground pork and dry-cured hams

ABSTRACT:  Seventy-five ground meat and fat samples of pork with varying composition of sodium chloride (0% to 16%), fat (1% to 82%), protein (1% to 46%), and water (13% to 76%) were scanned by X-ray computed tomography (CT) at 110 kV. The dependency of CT value on chemical composition and the linear relationships between sodium chloride (NaCl) and CT value were modeled. When all ground samples were used for modeling and no information of chemical composition was included in the model, the prediction error for NaCl was 2.8%. Adding information on fat or protein content to the model reduced the error to 1.6%. A minimal prediction error of 0.2% for NaCl was found when the variation in chemical composition was strongly reduced. In addition, 22 samples of dry-cured ham lean and fat tissues at different processing stages were CT scanned; their chemical compositions were 0% to 14% NaCl, 1% to 85% fat, 5% to 33% protein, and 7% to 76% water. The NaCl content in dry-cured ham samples was modeled with prediction errors of 0.6% to 2.1%, depending on which chemical component was included in the models. In general, predictions were improved if either the range of concentrations was reduced or information of chemical composition was included in the models. Important sources of error in the models were the reproduction error for ground samples, and for ham samples the analytical errors in determining the chemical composition.     

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).     

Determination of sodium chloride in pork meat by computed tomography at different voltages

Ground pork samples simulating the widely different chemical composition of hams during dry-cured ham production were produced and scanned by x-ray computed tomography (CT). Chemical composition accounted for most of the variation in CT values (97%). Tube voltage (80, 110, and 130 kV) affected CT value and the effect varied between different types of tissue. Sodium chloride (NaCl) was predicted in the ground samples with average prediction errors (RMSEP) as low as 0.2% to 1.0% NaCl. NaCl was also predicted in small samples of raw to dry-cured ham. When dry and fat ham samples were left out of the models, NaCl was predicted with a high precision (RMSEP 0.2% to 0.4% NaCl, R(2) > 0.99). CT can be used as a valuable, nondestructive tool to analyze distribution of and quantify NaCl in ham during dry-curing.     

火腿风味的低钠发酵肉制品品质及风味研究

以猪后腿肉为原料,利用发酵火腿生产工艺参数制成具有火腿风味的产品。采用乳酸钾和L-精氨酸替代30%钠盐用于加工,研究其对发酵肉制品水分活度、颜色、水分含量、蛋白质含量、质构特性、硫代巴比妥酸值等品质指标及产品风味的影响。结果表明:采用不同配比的乳酸钾和L-精氨酸替代30%的钠盐,在保证产品风味的同时,均能降低发酵肉制品中钠含量;结合理化指标及感官评定,采用9%L-精氨酸+21%乳酸钾或12%L-精氨酸+18%乳酸钾的效果最佳。     

Biochemical and sensory changes in dry-cured ham salted with partial replacements of NaCl by other chloride salts

The reduction of the content of sodium chloride in dry-cured ham was studied in to prevent the problems related to high sodium intake (i.e. the hypertension). One of the possibilities to reduce the sodium content is the partial replacement of sodium chloride by mixtures of potassium, magnesium and calcium chloride salts. The effect of two salting formulations (formulation II: 50% NaCl-50% KCl and formulation III: 55% NaCl, 25% KCl, 15 CaCl₂ and 5 MgCl₂) on the protease activity through the dry-curing process and on the sensory characteristics of the final product was evaluated and compared to those of control hams (formulation I, 100% NaCl). Sensory attributes were all affected in the hams containing CaCl₂ and MgCl₂ while hams containing 50% KCl and NaCl (formulation II) were better valued, except for the attribute taste probably due to the potassium contribution to bitter taste.     

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.     

Zn-porphyrin formation in cured meat products: Effect of added salt and nitrite

Zn-porphyrin (Zn-pp) was quantified by fluorescence spectroscopy in the cured and dry cured meat products: Parma ham, Iberian ham, dry-cured ham with added nitrite, cooked ham with added nitrite, raw ham meat, raw bacon and Karree-Speck. The highest amount of Zn-pp was found in dry-cured Parma ham and Iberian ham, while the use of nitrite as curing agent was found to inhibit completely the formation of Zn-pp in meat products. A positive correlation between both Zn content and Fe content and the logarithmic transformed Zn-pp content (measured as fluorescence intensity I_fl) was found for the different cured and dry cured meat products, with correlation coefficients of 0.79 (p < 0.001) and 0.71 (p < 0.01), respectively. Log I_fl correlates best with the Zn content, indicating that the formation of Zn-pp is proportional to the Zn content. A model system with vacuum packed pork in brine with different added levels of sodium chloride with or without nitrite and Zn acetate was investigated in order to further elucidate the mechanism of Zn-pp formation. Zn-pp increased with time (up to 42 days investigated) in non-cured meat and for meat cured solely with NaCl lower than 9%. Addition of nitrite or Zn(II) in the curing brine was found to inhibit formation of Zn-pp confirming the observations from the various cured meat products. It is suggested that a chloride anion assisted dissociation of iron from myoglobin could be rate-determining for Zn-pp formation in meat products.     

THE STUDY OF INGREDIENTS AND PROCESSING TECHNIQUES OF XUANWEI STYLE HAM

Xuanwei style ham is one of the famous dry-cured hams in the world. The influences of different ingredients and processing techniques on sensory properties, brine diffusing rate, chemical composition and hygienic quality of Xuanwei style cured ham were studied. Modified cured ham processing techniques were employed in this study. Massaging of green ham and injection of curing solution improved brine diffusing rate ( P <  0.05) and reduced curing time from the traditional 28 days to 21 days (weight of green ham about 13 kg). Ninety mg/kg sodium nitrite was used for improving cured ham color ( P <  0.05), and its residue still met the Chinese cured ham standard of 20 mg/kg. The hygienic and sensory qualities were not significantly affected by the addition of sodium ascorbate and polyphosphate ( P >  0.05).

PRACTICAL APPLICATIONS

The paper studied the Chinese famous Xuanwei dry-cured ham, modified curing ingredient and processing techniques of Xuanwei ham are beneficial for improving the ham quality and important to shorten the traditional cured ham processing procedure such as longer processing time and seasonal processing method to adapt to the new industrial procedures of manufacturing and marketing of Xuanwei cured ham.     

云南干腌火腿加工工艺及其品质影响因素研究进展

云南干腌火腿是一种重要的传统发酵肉制品,以猪后腿为原料,经腌制、风干、发酵等加工而成。云南干腌火腿主要有宣威火腿、撒坝火腿、三川火腿、老窝火腿、诺邓火腿及鹤庆火腿等,本文对云南干腌火腿加工工艺及干腌火腿品质影响因素进行综述,从原料肉、腌制条件、色泽及风味等几方面做了详细讨论,旨在为干腌火腿品质改进提供一定的理论参考。     

Lipid and protein oxidation and sensory properties of vacuum-packaged dry-cured ham subjected to high hydrostatic pressure

The effect of HHP treatment (600 MPa) on the oxidative stability of lipids and proteins of vacuum-packaged Iberian dry-cured ham and the impact on the sensory characteristics of the product was investigated. In order to assess how different commercial presentations are affected by HHP treatment, three different presentations of vacuum-packaged Iberian dry-cured ham were considered, namely, (i) intact format (IF) corresponding to non-sliced vacuum-packaged dry-cured ham, (ii) conventional-sliced format (CSF) corresponding to dry-cured ham slices placed stretched out in the package and (iii) alternative-sliced format (ASF) corresponding to dry-cured ham slices piled up horizontally. The oxidation of dry-cured ham lipids and proteins was enhanced by HHP-treatment with the presentation being highly influential on these oxidative reactions. Pre-slicing dry-cured ham results in a more susceptible product to oxidative reactions during pressurisation and subsequent refrigerated storage. Possible mechanisms, by which HHP-induced oxidative reactions would affect particular sensory traits in vacuum-packaged Iberian dry-cured ham such as colour, texture and flavour attributes, are discussed.     

Consumer satisfaction with dry-cured ham in five European countries

The objective is to investigate consumer satisfaction with dry-cured ham in five European countries. A logistic regression model has been fitted using data collected through a cross-sectional web-based survey carried out in Belgium, Germany, Denmark, Poland and Greece during January 2008 (n=2437 of which 2156 were dry-cured ham consumers). Satisfaction was evaluated as overall satisfaction, as well as specific satisfaction with healthfulness, price, convenience and taste. The findings show that the main determinant of overall satisfaction is taste satisfaction, hence, producers are recommended to focus on matching sensory acceptability of dry-cured ham. No significant between-country differences were found, reflecting the wide availability of this product in all countries. Consumer characteristics influenced their level of satisfaction. Men, older (age > 52 years) and frequent consumers of dry-cured ham consumption were more likely to be satisfied with dry-cured ham. Consumers trust the butcher's advice and they preferred purchasing dry-cured ham at a butcher shop rather than in a supermarket.     

Assay of Cathepsin D activity in fresh pork muscle and dry-cured ham

Different assays of cathepsin D activity in both porcine muscle and dry-cured ham extracts have been tested in order to find the best conditions for a reliable detection of cathepsin D in dry-cured meat products. The enzyme was effectively extracted with 0·2% (v/v) of Triton X-100.

Nucleases if present were not observed to interfere with the assays. The best conditions for a reliable detection of cathepsin D in dry-cured ham were found to be the incubation of the enzyme extract for 1 h at 45°C in a reaction mixture containing 0·60% (w/v) of haemoglobin in 0·2 sodium citrate buffer, pH = 3·7.     

A comprehensive review on molecular mechanism of defective dry-cured ham with excessive pastiness,adhesiveness, and bitterness by proteomics insights

Excessive bitterness, pastiness, and adhesiveness are the main organoleptic and textural defects of dry-cured ham, which often cause a lot of financial losses to manufacturers and seriously damage the quality of the product. These sensory and textural defects are related to the protein degradation of dry-cured ham. Proteomics shows great potential to improve our understanding of the molecular mechanism of sensory and textural defects and identify biomarkers for monitoring their quality traits. This review presents some of the major achievements and considerations in organoleptic and textural defects of dry-cured ham by proteomics analysis in the recent decades and gives an overview about how to correct sensory and textural defects of dry-cured ham. Proteomics reveals that muscle proteins derived from myofibril and cytoskeleton and involved in metabolic enzymes and oxygen transport have been identified as potential biomarkers in defective dry-cured ham. Relatively high residual activities of cathepsin B and L are responsible for the excessive degradation of these protein biomarkers in defective dry-cured ham. Ultrasound-assisted mild thermal or high-pressure treatment shows a good correction for the organoleptic and textural defects of dry-cured ham by changing microstructure and conformation of muscle proteins by accelerating degradation of proteins and polypeptides into free amino acids.     

Proteolytic and lipolytic modifications during the manufacture of dry-cured lacón,a Spanish traditional meat product: Effect of some additives

The extractability of sarcoplasmic and myofibrillar proteins, the myofibrillar proteins and their degradation products, classical nitrogen fractions, free amino acids, acidity of the fat, and free fatty acids were determined throughout the manufacturing process of dry-cured lacón, a traditional dry-salted and ripened meat product made in the northwest of Spain from the foreleg 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) on the proteolytic and lipolytic changes was also studied.     

Evolution of nitrate and nitrite during the processing of dry-cured ham with partial replacement of NaCl by other chloride salts

Nitrate and nitrite are commonly added to dry-cured ham to provide protection against pathogen microorganisms, especially Clostridium botulinum. Both nitrate and nitrite were monitored with ion chromatography in dry-cured hams salted with different NaCl formulations (NaCl partially replaced by KCl and/or CaCl(2), and MgCl(2)). Nitrate, that is more stable than nitrite, diffuses into the ham and acts as a reservoir for nitrite generation. A correct nitrate and nitrite penetration was detected from the surface to the inner zones of the hams throughout its processing, independently of the salt formulation. Nitrate and nitrite achieved similar concentrations, around 37 and 2.2 ppm, respectively in the inner zones of the ham for the three assayed salt formulations at the end of the process, which are in compliance with European regulations.     

Enzyme-assisted extraction for the HPLC determination of ochratoxin A in pork and dry-cured ham

The extraction of ochratoxin A from meat products is generally carried out using chlorinated organic solvents, such as chloroform or methyl chloride, acidified with hydrochloric or o-phosphoric acid. In this study, an innovative method was developed to extract ochratoxin A from pork and dry-cured ham samples. The method was based on an enzyme-assisted extraction with pancreatin in phosphate buffer pH 7.5. Pancreatin hydrolyses the proteins, so that ochratoxin A, kept in the ionised form, is easily extracted by the aqueous solution. After purification through an immunoaffinity column, ochratoxin A is determined by HPLC with fluorescence detection. The average recovery values were higher than 90.0% and the relative standard deviations were below 5.5%. The limits of detection and of quantification were 0.06 and 0.12 μg kg(-1), respectively. A comparison between the new enzyme-assisted extraction and an established chloroform method was carried out on six naturally contaminated samples of pork and on 40 samples of dry-cured ham. Significantly higher (p<0.001) values of ochratoxin A were obtained on dry-cured ham samples by the enzyme-assisted method.     

无硝干腌火腿中红色素形成机制研究进展

干腌火腿经过长时间腌制发酵成熟,富含生物活性物质,具有良好的感官特性。在传统干腌火腿加工过程中常添加硝盐（硝酸盐或亚硝酸盐）以获得稳定的色泽,然而,由亚硝酸盐与仲胺反应生成的亚硝胺具有致癌风险,已引起人们的广泛关注。研究发现,国外的著名干腌火腿如帕尔玛火腿,在腌制过程中不添加硝盐,其红色的主要贡献者被证实为Zn-原卟啉IX。本文综述了添加硝盐与未添加硝盐干腌火腿中红色素的研究进展,重点探讨Zn-原卟啉IX在无硝干腌火腿加工过程中的形成机制,以期为干腌火腿加工过程的色泽调控提供科学理论依据。     

Advances in the ultrasound characterization of dry-cured meat products

In this work, the feasibility of using non-contact ultrasonic techniques (air-coupled and scanning acoustic microscopy, SAM) for characterizing different dry-cured meat products was assessed. Air-coupled ultrasonic measurements were performed on vacuum packaged sliced dry-cured ham, and compared with contact measurements. The average ultrasonic velocity in dry-cured ham was 1846 ± 49 m/s and 1842 ± 42 m/s for air-coupled and contact measurements, respectively. The deviation (1% relative error) between both techniques was related to the influence of the heterogeneous structure and composition of dry-cured ham and the transducer focusing. The SAM was used to characterize dry-cured ham and chorizo samples. B-scan images for dry-cured ham and chorizo showed two dominant reflections from the sample, linked to reflections in the lean and fatty tissues. The results indicate that contact ultrasonic measurements could be replaced by the air-coupled technique, reducing the measuring time and the material handling. On the other hand, SAM technique allows the microscopic characterization of dry-cured meat products.     

Enzyme-assisted extraction for the HPLC determination of ochratoxin A in pork and dry-cured ham

The extraction of ochratoxin A from meat products is generally carried out using chlorinated organic solvents, such as chloroform or methyl chloride, acidified with hydrochloric or o-phosphoric acid. In this study, an innovative method was developed to extract ochratoxin A from pork and dry-cured ham samples. The method was based on an enzyme-assisted extraction with pancreatin in phosphate buffer pH 7.5. Pancreatin hydrolyses the proteins, so that ochratoxin A, kept in the ionised form, is easily extracted by the aqueous solution. After purification through an immunoaffinity column, ochratoxin A is determined by HPLC with fluorescence detection. The average recovery values were higher than 90.0% and the relative standard deviations were below 5.5%. The limits of detection and of quantification were 0.06 and 0.12?µg?kg^?1, respectively. A comparison between the new enzyme-assisted extraction and an established chloroform method was carried out on six naturally contaminated samples of pork and on 40 samples of dry-cured ham. Significantly higher (p?<?0.001) values of ochratoxin A were obtained on dry-cured ham samples by the enzyme-assisted method.