灵活气调包装 配合肉品市场

<正> 瑞士BELL AG集团在经济不景气的环境下,业务得以扩张,规模不断壮大,与其选用Multivac包装生产线不无关系。现荣幸邀请BELL AG公司计划与技术部经理Hanssmann先生接受访问,介绍该公司所选用的包装生产线的特点。(问:记者;答:Hanssmann先生) 可靠包装保证质量 问:请谈淡Multivac包装机的装置如何     

Shelf life of modified atmosphere packed cooked meat products: a predictive model

The effect of temperature, concentration of dissolved CO2 and water activity on the growth of Lactobacillus sake was investigated by developing predictive models for the lag phase and the maximum specific growth rate of this specific spoilage organism for gas-packed cooked meat products. Two types of predictive model were compared: an extended Ratkowsky model and a response surface model. In general, response surface models showed a slightly better correlation, but the response surface model for the maximum specific growth rate showed illogical predictions at low water activities. The concentration of dissolved CO2 proved to be a significant independent variable for the maximum specific growth rate as well as for the lag phase of L. sake. Synergistic actions on the shelf life-extending effect were noticed between temperature and dissolved CO2, as well as between water activity and dissolved CO2. The developed models were validated by comparison with the existing model of Kant-Muermans et al. (1997) and by means of experiments in gas-packed cooked meat products. Both developed models proved to be useful in the prediction of the microbial shelf life of gas-packed cooked meat products.     

Effect of gas composition on rabbit meat quality in modified atmosphere packaging

This study examines the effect of four types of modified atmospheres (MA), (A: 30% CO₂ + 70% O₂; B: 30% CO₂ + 30% O₂ + 40% N₂; C: 40% CO₂ + 60% N₂; D: 80% CO₂ + 20% O₂), on the quality of rabbit meat. Meat quality was assessed by examining pH, colour, drip loss (DL), cooking loss (CL) and shear force (SF). Similar values of pH were observed for all treatments and increased over time (p < 0.05). Acceptance of meat (on the basis of overall appearance) correlated (p < 0.001) with Chroma, time storage and type of MA. Samples packed with A were the most acceptable over time. Samples packed with D showed highest DL values, while in this same group CL values were highest (p < 0.05) only during the first 5 days post‐packing. SF values decreased with ageing, and in general similar values were observed for all treatments. Copyright © 2005 Society of Chemical Industry     

Thymol and modified atmosphere packaging to control microbiological spoilage in packed fresh cod hamburgers

A study on the use of mild technologies to produce packaged fish hamburgers was presented. In particular, the antimicrobial effect of some natural compounds (carvacrol, eugenol, thymol, green tea extract, rosemary extract, grapefruit seed extract and lemon extract), at various concentrations (500–10 000 ppm), was screened in vitro against the main fish spoilage micro‐organisms (Shewanella putrefaciens and Photobacterium phosphoreum). Lemon extract and thymol, in combination with modified atmosphere packaging, showed the greatest inhibition activity, therefore, thymol was subsequently used as an ingredient for producing fish hamburgers. Results pointed out that this combination is effective in controlling the growth of microbial species mainly involved in fresh fish spoilage; in particular, it significantly (P < 0.05) reduced the growth rate of bacterial population, performing about 4.8 log CFU g^?1 and 6.5 log CFU g^?1 reduction of the hydrogen sulphide producing bacteria and psychrotrophic aerobic specific spoilage organisms cell load, respectively, if compared with the control.     

Novel approach to oxygen control in modified atmosphere packaging of bakery products

PDA plates inoculated with mould spores were packaged in air and in a mixture of CO₂/N₂ (60 : 40) with headspace oxygen adjusted to range from <0·05% to 10% (v/v) and stored at 25°C. Those packaged in air showed mould growth after 1–1·5 d, while those in the gas mixture showed growth between 4–6 d after headspace oxygen reached a minimum concentration of 0·4%. Uninoculated plates packaged in air showed no change in headspace oxygen concentration over 30 d at 25°C, while those in the gas mixture with initial headspace oxygen of <0·05% showed a steady increase of oxygen, through packaging film permeability, at an average rate of 0·06%/d. If uninoculated plates were packaged in air together with a sachet of oxygen absorbant called Ageless, the headspace oxygen was quickly reduced to <0·05% within 9 h and remained unchanged thereafter.Crusty rolls with a_w of 0·95 and pH of 5·62 developed mould after 5–6 d when packaged in air, 9–11 d in 100% N₂ and 16–18 d in CO₂/N₂ (60 : 40). However, when Ageless was incorporated into all the packages the product remained mould free for >60 d. This study shows that oxygen absorbants offer the bakery industry a viable alternative to gas flushing.     

Development of shelf-life kinetic model for modified atmosphere packaging of fresh sliced mushrooms

Mushrooms are highly perishable and their shelf-life depends on processing, package properties and environmental conditions during storage and distribution. The aims of this work were to evaluate the effect of temperature and number of film perforations on quality and develop shelf-life kinetic model for a modified atmosphere packaging (MAP) for sliced button mushrooms. Sliced mushrooms were packed in a tray, covered with cellophane film, and stored for 7 days at four levels of temperature (0, 5, 10, and 15 °C) and three levels of perforations at each temperature ranging the number of perforations from 1 (58 perforations per m²) to 6 (349 perforations per m²). Headspace gas composition and quality parameters (weight loss, pH, firmness and colour) were measured throughout the storage period. Increasing the storage temperature required an increase of the number of perforations in order to obtain the optimum MAP conditions. Temperature had a significant effect (p < 0.05) on quality of sliced mushrooms. Firmness was identified as a critical quality parameter; therefore, a kinetic model was developed to describe the influence of temperature on firmness and predict shelf-life of sliced mushrooms. Fresh sliced mushrooms had a shelf-life of 1, 2, 4, and 7.5 days at 15, 10, 5, and 0 °C, respectively, under optimum MAP conditions.     

Effect of grafting and modified atmosphere packaging on eggplant quality parameters during storage

The physico‐chemical parameters (pH, mechanical firmness and vitamin C) and sensory parameters of grafted and ungrafted eggplant plants were studied in relation to storage time (up to 17 days at 10 °C). Eggplant plants of cultivar ‘Tsakoniki’ were grafted on Solanum torvum and S. sisymbriifolium rootstocks in order to avoid the soil borne disease caused by Verticillium dahliae. The fruits were stored under modified atmosphere packaging (MAP). Vitamin C was negatively affected by grafting it storage, while MAP prolonged the shelf life. Although pH was not affected by grafting but was positively affected by MAP. Flesh firmness was negatively affected by grafting and reduced over storage, but positively affected by MAP. Sensory analysis showed higher ratings of fruits from ungrafted plants for sweetness, acceptance and hardness whereas no difference was detected for overall acceptance. Fruits stored under MAP were better maintained compared with those stored in air.     

气调包装中氧气含量对冷鲜猪肉品质的影响

为研究气调包装中氧气含量对冷鲜猪肉贮藏期间品质的影响,采用高阻隔性包装材料及两种不同气体比例(80%O2+20%CO2和50%O2+20%CO2+30%N2)对冷鲜猪肉进行气调包装,以托盘包装为对照,对冷鲜猪肉贮藏期间的菌落总数、色差、保水性、剪切力及包装内气体组成等指标进行检测分析。结果表明:气调包装组能够维持贮藏过程中包装盒内气体成分基本恒定;与托盘包装相比,50%O2气调包装可延长冷鲜猪肉货架期6 d,80%O2气调包装冷鲜猪肉货架期更长;气调包装组冷鲜肉红度值a*、黄度值b*显著高于(P0.05)托盘包装组;气调包装冷鲜猪肉保水性比托盘包装差,而两气调包装组之间无显著差异(P0.05);贮藏过程中气调包装组剪切力值大于托盘包装组(P0.05),80%O2气调包装组剪切力值小于50%O2气调包装组(P0.05);结论:气调包装会对冷鲜猪肉保水性、嫩度等品质造成一些不良影响,但可显著延长其货架期,采用80%O2比50%O2保鲜效果更好。     

Sprouting and quality control of fresh ginger rhizomes by modified atmosphere packaging with film perforation

The quality of ginger rhizomes packaged in low density polyethylene bags (modified atmosphere packaging — MAP) without perforations (P-0), with 2 perforations (P-2), and 12 perforations (P-12) have been investigated for 5 months at 12±1°C. Sprouting and rotting rates of ginger in P-2 and P-12 were lower than ginger in P-0. Weight loss was higher in P-12 than P-0 and P-2. Surface L* (lightness) and a* (redness) values in P-2 and P-12 were lower and higher, respectively, than those found for P-0. Sensory appearance and overall acceptability were rated significantly better in P-2 and P-12 than in P-0. Internal color, firmness, soluble solids, and pH of ginger in MAP were not affected by presence of perforations. Therefore, MAP with the appropriate number of perforations (in this work, 2 perforations) could be a useful method to control sprouting and maintain quality except for surface color of stored ginger rhizomes.     

Irradiation and modified atmosphere packaging for the control of Listeria monocytogenes on turkey meat.

When radiation-sterilized ground turkey meat was inoculated with Listeria monocytogenes, packaged under mixtures of nitrogen and carbon dioxide, and irradiated with gamma-radiation doses of 0 to 3.0 kGy, there was a statistically significant (P < 0.05), but probably not a biologically significant, lower (0.39 log) predicted bacterial survival in the presence of 100% carbon dioxide than in the presence of 100% nitrogen. Possibly because all atmospheres contained oxygen and because a response surface design was used, gamma-radiation resistance was not significantly (P < 0.05) different in air than in modified atmosphere packaging (MAP) mixtures containing 5% O2 or containing 20, 40, 60, and 80% CO2 and balance N2. The antilisterial effects of MAP mixtures containing 17.2, 40.5, and 64% CO2 and balance N2 were compared to those associated with air and vacuum packaging on turkey inoculated with approximately 5 x 10(3) CFU/g. Samples were irradiated to doses of 0, 0.5, 1.0, 1.5, 2.0, and 2.5 kGy and were stored at 7 degrees C for up to 28 days. Irradiation treatments were significantly more lethal in the presence of air packaging than in either vacuum packaging or MAP, and in those samples that received >1.0 kGy, there was a concentration-dependent CO2 inhibition of L. monocytogenes multiplication and/or recovery.     

Diversity of lactic acid bacteria from modified atmosphere packaged sliced cooked meat products at sell-by date assessed by PCR-denaturing gradient gel electrophoresis

The predominant lactic acid bacteria (LAB) microbiota associated with three types of modified atmosphere packaged (MAP) sliced cooked meat products (i.e. ham, turkey and chicken) was analyzed at sell-by date using a combination of culturing and molecular population fingerprinting. Likewise routine analyses during industrial MAP production, meat samples were plated on the general heterotrophic Plate Count Agar (PCA) and on the LAB-specific de Man, Rogosa, Sharpe (MRS) agar under different temperature and atmosphere conditions. Subsequently, community DNA extracts were prepared from culturable bacterial fractions harvested from both media and used for PCR targeting the V3 hyper-variable region of the 16S rRNA gene followed by denaturing gradient gel electrophoresis (DGGE) of PCR amplicons (PCR-DGGE). Irrespective of aerobic or anaerobic incubation conditions, V3-16S rDNA DGGE fingerprints of culturable fractions from PCA and MRS medium displayed a high level of similarity indicating that LAB constituted the most dominant group in the culturable bacterial community. Comparison of DGGE profiles of fractions grown at 20, 28 or 37 °C indicated that part of the culturable community consisted of psychrotrophs. Four DGGE bands were common among cooked ham, turkey and chicken products, suggesting that these represent the microbiota circulating in the plant where all three MAP product types were sliced and packaged. Based on band sequencing and band position analysis using LAB reference strains, these four bands could be assigned to Lactobacillus sakei and/or the closely related Lactobacillus fuchuensis, Lactobacillus curvatus, Carnobacterium divergens and Leuconostoc carnosum. In conclusion, the PCR-DGGE approach described in this study allows to discriminate, identify and monitor core and occasional LAB microbiota of MAP sliced cooked meat products and provides valuable complementary information to the current plating procedures routinely used in industrial plants.     

Extending the quality of fresh strawberries by equilibrium modified atmosphere packaging

The impact of equilibrium-modified atmosphere packaging (EMAP) technology on extension quality [pH, acidity, brix, color (L, a, Chroma, hue)] and texture profile analyses of fresh strawberries was studied and compared during storage. Cast polypropylene (CPP), linear low density polyethylene (LLDPE) and polyethylene-terephthalate (PET)/Ethylene vinyl alcohol (EVOH)/Polyetlene-low-acetyl fractions (LAF) were used as heat-sealed lid and polyvinyl chloride (PVC/PE) tray with the purpose of obtaining equilibrium atmospheres. Among the various films used, pH of fresh strawberry was 3.275 at initial days, and increased to 3.39- for LLDPE; 3.42 for CPP and 3.44 PET/EVOH-LAF at the end of 10 days’ storage. Acidity values were 0.609 mg ml⁻¹ and decreased to 0.56 mg ml⁻¹ for LLDPE; 0.47 mg ml⁻¹ for CPP and 0.49 mg ml⁻¹ for PET/EVOH-LAF at end of storage. The strawberry brix had evolved from the initial 7.125 and reduced to about from 5.6 to 6.07 at the end of the storage. At the end of the storage, the strawberry L values had not significantly changed from the initial from 29.10 (L) to 28.9–26.46. Initial values of the firmness were 1,089 gf and reduced with ranged from 769 gf to 527 gf at end of the 10-day storage period. All the parameters in texture profile analyses showed a decline, except adhesiveness and springiness and used potential indicators of fresh strawberries. The overall results expressed that strawberry quality can be maintained effectively at least for 10 days using various polymeric lid films. PET/EVOH-LAF and CPP were much more effective then LLDPE due to barrier properties during storage periods. Quality of strawberry packaged with suitable high-barrier lid films have been prolonged significantly.     

Effects of gas composition in modified atmosphere packaging on the meat quality of Spanish Manchega lamb

The effects of four types of packaging atmosphere, each with a different gas composition (20–80% CO₂), on the meat quality of Spanish Manchega lamb were examined in order to suggest a gas composition for optimal preservation. Meat quality was assessed by pH, colour (L*,a* and b* values), water‐holding capacity (WHC), cooking loss (CL) and shear force (SF). Gas composition affected all parameters except L* and SF. The pH values decreased significantly in samples packed with 80% CO₂ but remained constant in the other groups. The b* values were lower in samples packed without O₂ than in the other groups and increased with time. However, the a* values decreased in all groups with time. Samples packed in low‐CO₂ atmosphere tended to lose more water (ie to have less WHC and show more CL). The SF values decreased with time, and similar values of this parameter were observed for all treatments. © 2001 Society of Chemical Industry     

Effect of modified atmosphere packaging on the shelf-life of coated, whole and sliced mushrooms

Whole and sliced fresh mushrooms (Agaricus bisporus) were packaged with PVC wrap or two polyolefins (PD-941 and PD-961) films after coating with CaCl₂ and chitosan. Package gas composition, color, weight loss and maturity were measured during storage at 12 °C and 80%RH. For PD-961, the highest in-package concentration occurred during the first day of storage regardless of treatments, while wrap and PD-941 showed varying degrees in-package concentration with different processes and coatings. The whiteness of whole mushrooms varied significantly with the type of coating, but not with the type of films. The extent of darkening was greater in coated whole mushrooms than in sliced ones. Weight loss occurred in all packages and varied from 3 (g/100 g) to about 7 (g/100 g) after 6 days of storage. Due to a lower permeability, PD-961 packages had the lowest weight loss. The type of packaging films significantly affected the maturity index, where PD-961 most effectively lowered maturity index for both whole and sliced mushrooms, thus extending the shelf-life. The type of coating did not appear to affect maturity index except for the wrap package where chitosan coating markedly lowered the maturity index of sliced mushrooms.     

调理配料对生鲜猪肉高氧MAP产品品质的影响研究

新鲜猪肉为原料,研究以食盐、复合香辛料、料酒添加量作为正交实验因素的生鲜调理猪肉在气调包装下的品质指标的变化。结果表明:与鲜肉相比,生鲜调理猪肉红度值提高,剪切力值与水分含量有小幅度上升,在4℃储藏过程中,生鲜调理猪肉色泽逐渐变暗(表现为a值下降),剪切力值呈现上升趋势,但货架期(5d)内生鲜调理猪肉的色泽与嫩度仍在可接受范围内,食盐与复合香辛料以及料酒含量对剪切力值的影响有显著交互作用(p<0.05)。综合正交实验直观分析及以剪切力值为目标函数的回归优化,最终得出配方为食盐:2%,香辛料:1%,料酒:7%。      

调理配料对生鲜猪肉高氧MAP产品品质的影响研究

新鲜猪肉为原料,研究以食盐、复合香辛料、料酒添加量作为正交实验因素的生鲜调理猪肉在气调包装下的品质指标的变化.结果表明:与鲜肉相比,生鲜调理猪肉红度值提高,剪切力值与水分含量有小幅度上升,在4℃储藏过程中,生鲜调理猪肉色泽逐渐变暗(表现为a值下降),剪切力值呈现上升趋势,但货架期(5d)内生鲜调理猪肉的色泽与嫩度仍在可接受范围内,食盐与复合香辛料以及料酒含量对剪切力值的影响有显著交互作用(P＜0.05).综合正交实验直观分析及以剪切力值为目标函数的回归优化,最终得出配方为食盐:2％,香辛料:1％,料酒:7％.     

Effect of muscle,ageing time and modified atmosphere packaging conditions on the colour,oxidative and microbiological stability of packed beef

The objective of this study was to evaluate the influence of two different vacuum ageing times (7 and 14 days) and the impact of the modified atmosphere packaging (MAP) configuration (gas/product ratios: 0.5 and 1 and gas composition: 70% O₂ + 30% CO₂ and 40% O₂ + 30% CO₂ + 30% N₂) on the quality of fresh beef during subsequent storage at 4 °C. For this purpose, three separate experiments were performed. For each experiment, two different muscles (Longissimus dorsi and Biceps femoris) were sampled from four double‐muscled Belgian Blue beef carcasses. Next to colour, also the evolution in microbial load, pH, O₂ and CO₂ in the headspace and lipid oxidation at the meat surface were evaluated. A vacuum ageing for 14 days compared with 7 days resulted in a higher initial microbial load on the day of MAP packaging, which resulted finally in a significantly shorter shelf life. This ageing effect was less pronounced on the colour stability and lipid oxidation of the meat samples. No significant influence of the packaging configuration on any of the analysed parameters (colour, microbial load, pH and lipid oxidation at the meat surface) was observed.     

A second look at the influence of birth weight on carcass and meat quality in pigs

To re-examine the relationship of birth weight with carcass and meat quality of pigs at market weight, offspring (n=378) of 63 sows were assigned to three birth weight groups; 25% low weight (LW), 50% middle weight (MW), and 25% heavy weight (HW), with runts (<800g) being excluded. LW pigs exhibited the lowest postnatal growth performance, the lowest lean mass and the greatest degree of fatness in terms of perirenal fat compared with MW and HW pigs. Only in females, but not in male castrates, the lean percentage was highest in HW pigs. Characteristics of longissimus muscle technological quality declined either in LW (pH, drip loss) or HW (conductivity, lightness) compared with MW pigs. In contrast, intramuscular fat percentage (IMF) was highest in LW pigs. The results suggest that the most desirable carcass composition is obtained with HW pigs, whereas optimum technological pork quality, except for IMF, is achieved with MW pigs.     

The effects of modified atmosphere packaging, EDTA and oregano oil on the quality of chicken liver meat

Fresh chicken liver meat was packaged in air or under modified atmosphere packaging (MAP; 30%CO₂/70%N₂) and stored under refrigeration (4 °C). The following treatments were used: A (control samples, air packaging), AE [(EDTA (20 mM), air packaging)], M (MAP), ME (EDTA, stored under MAP), MER1 [(EDTA, oregano oil (0.1% v/wt), stored under MAP)] and MER2 [(EDTA, oregano oil (0.3% v/wt), stored under MAP)]. Quality evaluation of product stored under above packaging conditions and treated with EDTA and oregano oil was conducted using microbiological, chemical and sensory analyses. Based on mesophilic total viable counts (TVC) a microbiological shelf-life extension of 7, 9, 15 or > 15 days was obtained for M, ME, MER1 or MER2 liver samples, respectively, compared to the control's (A) shelf-life of 3 days. Air-packaged liver samples showed higher pH values in the first 8 days of storage compared to M, ME, MER1 and MER2 samples, with the latter showing a significant decrease at the end of the storage period. Interestingly, the presence of the oregano oil in MER1 and MER2 liver resulted in a lower production of TBA compared to all other samples. Based on sensory analysis, MER1 and MER2 extended the shelf-life of chicken liver by 14–15 days, while treatments M and ME by 7 and 9 days, respectively. Our results support the hypothesis that the shelf-life of chicken liver meat may substantially be extended (by almost 3 times the usual product's shelf-life using a natural antimicrobial combination (EDTA, oregano oil and MAP).     

Effects of modified atmosphere packaging (MAP) on the microbiological quality and shelf life of ostrich meat

Effects of various concentrations of O₂/CO₂ in modified atmosphere packaging on the microbiological quality and shelf-life of ostrich meat was investigated. Nine–12 months old ostriches were used. The iliofibularis muscle was cut into small cubes that were divided into five groups and then separately packaged under various gas mixes: air and O₂:CO₂:N₂ ratios of 80:20:0, 60:20:20, 60:40:0, and 40:40:20, using 2 different headspace ratios (1:1 and 3:1). The packaged meats were kept at 4 °C for 10 days and were analysed microbiologically, physico-chemically and sensorially. As a result, the meat quality and shelf-life of ostrich meat under various gas compositions were improved; microbial growth was delayed due to high CO₂ usage and shelf-life was increased by 5–7 days. However, an undesired loss of red colour of the ostrich meat may affect consumer acceptance.