贮藏温度和气调包装对鸡蛋保鲜效果的影响

为了延长鸡蛋保鲜期,研究在室温(25℃)和冷藏(4℃)条件下不同配比CO2、O2、N2三元混合气体包装对鸡蛋保鲜效果影响,结果表明:鸡蛋采用气体组分为50％CO2、7％～11％O2、39％～43％N2的气调包装贮藏保鲜,室温下贮藏30d仍保持AA级,而不包装室温贮藏30 d降到了B级;不包装冷藏也可延长鸡蛋保鲜期,但失重率相对较高;气调包装与冷藏结合对鸡蛋的保鲜效果不是2种处理的保鲜效果之和,与气调包装室温贮藏的保鲜效果相似.50％CO2、7％～11％O2、39％～43％N2三元气体包装、室温贮藏可实现鸡蛋就地贮藏,试验为鸡蛋贮藏保鲜提供参考.     

The role of packaging film permselectivity in modified atmosphere packaging

Modified atmosphere packaging (MAP) is commercially used to increase the shelf life of packaged produce by reducing the produce respiration rate, delaying senescence, and inhibiting the growth of many spoilage organisms, ultimately increasing product shelf life. MAP systems typically optimize O(2) levels to achieve these effects while preventing anaerobic fermentation but fail to optimize CO(2) concentrations. Altering film permselectivity (i.e., beta, which is the ratio of CO(2)/O(2) permeation coefficients) could be utilized to concurrently optimize levels of both CO(2) and O(2) in MAP systems. We investigated the effect of modifying film permselectivity on the equilibrium gas composition of a model MAP produce system packaged in containers incorporating modified poly(ethylene) ionomer films with CO(2)/O(2) permselectivites between 4-5 and 0.8-1.3. To compare empirical to calculated data of the effect of permselectivity on the equilibrium gas composition of the MAP produce system, a mathematical model commonly used to optimize MAP of respiring produce was applied. The calculated gas composition agreed with observed values, using empirical respiration data from fresh cut apples as a test system and permeability data from tested and theoretical films. The results suggest that packaging films with CO(2)/O(2) permselectivities lower than those commercially available (<3) would further optimize O(2) and CO(2) concentration in MAP of respiring produce, particularly highly respiring and minimally processed produce.     

Glucosinolates in mixed-packaged mini broccoli and mini cauliflower under modified atmosphere

Contents of total and individual glucosinolates of mini broccoli cv. Milady and mini cauliflower cv. Clarke were assessed to determine the effect of modified atmosphere packaging on postharvest glucosinolate dynamics of mixed mini Brassica vegetables. Therefore, mixed-packaged mini broccoli and mini cauliflower stored in food trays sealed with two different microperforated biaxial-oriented polypropylene films for up to 7 days at 8 degrees C were analyzed. The results indicate that modified atmosphere at 8% O2 + 14% CO2 was a suitable gaseous combination to maintain aliphatic and indole glucosinolates in mini broccoli for 7 days after an initial decrease at 4 days. In contrast, modified atmosphere at 1% O2 + 21% CO2 resulted in the best retention of indole glucosinolates of mini cauliflower for 7 days and also of aliphatic glucosinolates after an initial decrease at 4 days. Thus, to maintain glucosinolates and external appearance and to prevent off-odor, mini broccoli and mini cauliflower should be packed separately in suitable altered gas composition.     

Stabilization of aroma compounds through sorption-release by packaging polymers

Plastic packaging materials are often associated to aroma losses and to a decrease of the organoleptic quality of foods. This work defines situations where, on the contrary, plastics play a regulating role on the concentration of reactive aroma compounds in foods. These systems can be described by a two step mechanism; first, aroma is sorbed in the polymer, while the fraction in solution degrades quickly; in a second step, as the concentration is close to zero in the solution, the polymer liberates progressively the sorbed aroma back to the food. A simple numerical model is proposed, describing competitive processes of aroma degradation in solution and sorption by a polymer in contact with a homogeneous aqueous food. The classical limonene/low density polyethylene (LDPE) system is studied experimentally for the validation of the model: in an acidic medium, limonene both degrades quickly and is sorbed quickly, with a large solubility in LDPE. To define which aroma packaging systems could also display this interesting behavior, all types of possible interactions, using thermodynamic and kinetic parameters describing most practical situations, are simulated. For that purpose, 35 values of reference diffusion coefficients and 35 partition coefficients of usual aroma compounds between polymers and water have been measured and combined with the few available data from literature. The situations where polymers regulate the aroma concentration in food correspond to large partition coefficients (above 10), large diffusion coefficients (>10(-9) cm2 x s(-1)), and large degradation constants.     

气调包装对松籽常温贮藏生理和品质变化的影响

以朝鲜红松带壳松籽和去壳松仁为试材,将其分别放在30 μm紫色聚氯乙烯袋、30 μm白色聚氯乙烯袋和40 μm白色聚乙烯袋中进行自发气调贮藏,研究了常温下（20～30℃）贮藏180 d期间松籽种仁的生理、品质和脂肪酸氧化变化。结果表明：与40 μm聚乙烯袋相比,30 μm紫色聚氯乙烯袋与30 μm白色聚氯乙烯袋可以形成相对低O2高CO2的贮藏条件,能有效降低带壳松籽和去壳松仁的呼吸速率和可溶性总糖的损耗,提高种仁的贮藏优品率;同时可以较好地防止总脂肪的降解,抑制酸价、过氧化值的升高和碘价的降低。综上所述,30 μm聚氯乙烯袋可以较好地保持松籽品质,相同气调包装贮藏下带壳松籽的贮藏品质优于去壳松仁。     

气调包装条件下果蔬呼吸强度模型的研究进展

该文综述了国内外近几十年来气调包装(MAP)条件下果蔬呼吸强度模型的研究情况。探讨了在一定的贮藏时间内果蔬呼吸强度与袋内氧气浓度、二氧化碳浓度和温度的关系以及利用计算机技术进行MAP的最佳设计等方面的问题,从而为MAP技术更好地应用于果蔬保鲜提供参考。     

红富士苹果自发气调保鲜技术研究

采用5种不同保鲜膜包装，在0℃和10℃条件下，研究不同改性聚乙烯保鲜膜和聚氯乙烯保鲜膜、包装量对红富士苹果自发气调贮藏保鲜效果与原理，为红富士苹果冷藏保鲜和保鲜膜筛选提供依据。结果表明：不同红富士苹果保鲜膜包装内10 d左右O₂和CO₂浓度达平衡值。0℃条件下不同包装的O₂平衡值为12%～19%，CO₂为1.8%～5.0%，10℃条件下不同包装的O₂平衡值为5%～16%，CO₂为3.5%～8.0%。同样条件下2#保鲜膜包装内O₂最低、CO₂最高。各保鲜袋内虎皮病发生率高低顺序为：2#＞1#＞3#＞5#。包装量越大，温度越高，虎皮病发生率越大、乙醇和乙醛含量越高。利用富士专用保鲜膜和适宜的PE保鲜膜包装贮藏7个月，红富士苹果质量商品价值基本不变。     

Irradiation and modified atmosphere packaging effects on residual nitrite,ascorbic acid,nitrosomyoglobin, and color in sausage

The present study was undertaken to evaluate the irradiation and modified atmosphere packaging effects on emulsion-type cooked pork sausage during storage for 4 weeks. CO(2) (100%), N(2) (100%), or 25% CO(2)/75% N(2) packaged sausage were irradiated at 0, 5, and 10 kGy, and residual nitrite, residual ascorbic acid, nitrosomyoglobin (NO-Mb), color values, and their correlation were observed. Irradiation significantly reduced the residual nitrite content and caused partial reduction of NO-Mb during storage. No difference was observed in ascorbic acid content by irradiation. Irradiation decreased the Hunter color a value of sausage. CO(2) or CO(2)/N(2) packaging were more effective for reducing residual nitrite and inhibiting the loss of the red color of sausage compared to N(2) packaging. Results indicated that the proper combination of irradiation and modified atmosphere packaging could reduce the residual nitrite in sausage with minimization of color change.     

果蔬气调包装理论研究进展

气调包装是一种可延长新鲜水果货架寿命的重要技术。气调包装的质量主要取决于包装内气体成分、温湿度的调节。建立气调包装的理论模型是保证气调包装质量、进行气调包装系统设计的关键。该文综述了国内外这方面的研究成果,着重论述了果蔬呼吸模型、呼吸速率的测定方法、包装内外气体交换模型、包装内温度与湿度变化数学模型,并分析了目前研究存在的不足,为果蔬气调包装的深入研究提供参考。     

Influence of physicochemical interactions between amylose and aroma compounds on the retention of aroma in food-like matrices

In food matrices, where starch is often used as a gelling or texturing agent, the occurrence of amylose-aroma complexes and their effect on the release of aroma compounds are difficult to determine. Indeed, thick or gelled systems are known to reduce the diffusion rate of flavor molecules, resulting in an increase of retention. Moreover, interactions between aroma compounds and matrix components might increase the retention of aroma compounds. The complexing behavior of three aroma compounds with amylose was studied by DSC and X-ray diffraction to determine the relative importance of these two factors. Their interaction properties were different: two of them formed complexes, and the third did not. These aroma compounds were added in food matrices containing different starches that induced different textures. Their retention was studied by static headspace analysis. The retention of aroma compounds appeared to depend on the amylose/amylopectin ratio of starch, both from the formation of complexes and by a viscosity effect.     

天然保鲜剂与气调包装对牛肉火腿切片货架期的影响

该文以真空包装组为对照,在9℃、光照贮藏条件下,采用天然保鲜剂和气调包装对牛肉火腿切片进行了保鲜试验。结果表明：真空包装组(对照组)中的乳酸菌数量上升很快,28 d时就已大大超过6.70 log(cfu·g)^-1。随着乳酸菌的生长繁殖,各处理组产品的pH值不断下降。气调包装(60%CO₂+40%N₂)未显示出明显的抑菌作用,气调包装产品的a^*值(红度)随着贮藏时间的延长显著下降(p<0.05),褪色明显。天然保鲜剂(150 mg/kg Nisin+0.3%茶多酚)对乳酸菌有很好的抑制作用,采用切片后浸渍方式比腌制前添加方式的效果更好,能够延长牛肉火腿切片的货架期,保鲜剂对产品a^*值影响不明显(p＞0.05)。天然保鲜剂、气调包装对硫代巴比妥酸反应物(Thiobarbituric acid reactive substances, TBARS)变化的影响都不大(p＞0.05)。     

Influence of packaging on the aroma stability of strawberry syrup during shelf life

Different types of packaging (glass bottle, PVC, and PET) were compared for the preservation of aroma quality of a strawberry syrup during shelf life. Esters, alcohols, and aldehydes were analyzed by solid-phase micro-extraction (SPME) and solvent extraction. During storage, hydrolysis of esters in acids and alcohols led to a modification of the aroma profile which can be explained by the replacement of "fruity" and "fresh" notes by "dairy note" in the syrup. Aroma compounds that are responsible for fruity notes, such as methyl cinnamate, methyl anthranilate, and methyl dihydrojasmonate, were strongly reduced after 90 days. This could be explained by a selective interaction of these compounds with the polymer matrix (PET or PVC). After 330 days, a later and important decrease of the "fruity notes" occurred in both PETs; so PVC2 and the glass bottle were found to be able to maintain a balanced aroma for long-term storage.     

Maintaining quality of fresh-cut mangoes using antibrowning agents and modified atmosphere packaging

Treatments to inhibit browning and decay and prolong shelf life of fresh-cut mangoes were investigated. Combinations of antibrowning agents and modified atmosphere packaging (MAP) resulted in a reduction of browning and deterioration of fresh-cut mangoes stored at 10 degrees C. Combinations of several browning inhibitors were more effective than those applied individually. Among these treatments, solutions containing 4-hexylresorcinol (0.001 M) (HR) plus potassium sorbate (0.05 M) (KS) and HR plus KS plus D-isoascorbic acid (0.5 M) (ER) reduced changes in color (L, a, and b) and microbial growth and did not affect sensory characteristics of fresh-cut mangoes. In general, these treatments did not affect significantly the changes in organic acids and sugar content of slices during the 14 days of storage at 10 degrees C. High humidity created in the in-package atmosphere alleviated tissue dryness and was an important factor in the ability of the antibrowning solutions to prevent browning and decay. It appears that the maintenance of quality of fresh-cut mangoes is more related to particular combinations of the antibrowning agents used rather than the modified atmosphere created inside the package. HR + ER + KS treatment in combination with MAP could be used to inhibit browning, decay, and deterioration of fresh-cut mangoes.     

不同气调包装对冷藏鱼糜制品品质的影响

为分析不同气调包装对鱼糜制品冷藏过程中品质的影响,研究以鱼糜制品中的鱼丸为对象,通过测定其在 （0±0.5）℃冷藏过程中的菌落总数、理化和感官等指标的变化,评价气调包装的保鲜效果。气调包装条件分别为空气包装（对照）、低氧气调包装（60%CO2+10%O2+30%N2,均为体积分数,下同）、无氧气调包装（60%CO2+40%N2）、含保鲜剂的无氧气调包装（60%CO2+40%N2+保鲜剂）。结果表明,0℃下鱼丸在空气包装下贮藏32 d和低氧气调包装下贮藏42 d后菌落总数分达到8.7×104 cfu/g和8.5×104 cfu/g,超过规定的卫生标准;而无氧气调包装可使鱼丸的货架期达到47 d（菌落总数4.3×104 cfu/g）以上,含保鲜剂的无氧气调包装可使鱼丸货架期延长至52 d（菌落总数0.98×104 cfu/g）以上,并且能降低脂肪氧化程度;两组无氧气调包装样品在冷藏期间其pH值、TBA（硫代巴比妥酸）值和感官等指标都优于低氧气调包装和空气包装。无氧气调包装或结合生物保鲜剂包装能更好地延长冷藏鱼丸的货架期。     

气调包装技术用于虾皮保鲜的效果研究

为改进虾皮贮藏质量,延长货架期,研究了气调包装(Modified Atmosphere Packaging)对虾皮的保鲜效果。采用3种不同浓度配比的N₂和CO₂气体和真空包装等方法对虾皮进行包装,分别于5℃、室温和35℃下贮藏。检测虾皮感观、色差、菌落总数和脂肪含量。结果表明：低温有利于虾皮保鲜,高浓度CO₂气调贮藏能抑制虾皮中的微生物繁殖,减缓脂肪蚝蛤败速度,但CO₂浓度过高易使虾皮产生异味,影响感观品质。气调与低温结合可延长虾皮的保鲜期2个多月,推荐的气调气体比例为70%N₂/30%CO₂,低温冷藏。     

生物保鲜剂结合气调包装对带鱼冷藏货架期的影响

为了延长带鱼冷藏货架期,以空气包装组为对照,在（4±1）℃冷藏条件下,采用复合生物保鲜剂涂膜及保鲜剂结合气调包装对带鱼进行保鲜试验。以感官评分、细菌总数、挥发性盐基氮值（total volatile base nitrogen,TVB-N）、pH值、硫代巴比妥酸值（the 2-thiobarbituric acid,TBA）和汁液流失率为指标,测定带鱼冷藏过程中的品质变化。结果表明：空气包装组带鱼冷藏货架期为4 d,复合生物保鲜剂（1.0%壳聚糖＋0.4%茶多酚）具有良好的抑菌保鲜作用,高浓度CO2气调包装带鱼汁液流失较为严重,生物保鲜剂结合60%CO2＋10%O2＋30%N2气调包装组保鲜效果最为显著,冷藏贮存20 d,带鱼的细菌总数为5.59 lg(cfu/g),TVB-N值为19.39 mg/100 g,仍处在带鱼二级鲜度之内,可将冷藏带鱼货架期延长至20d,是对照组的5倍,且能较好地维持新鲜带鱼感官品质,以期为带鱼的保鲜提供一定的参考。     

Browning evaluation of ready-to-eat apples as affected by modified atmosphere packaging

The color and polyphenol oxidase (PPO) activity of fresh-cut Golden delicious apples were evaluated throughout cold storage under modified atmospheres. The shelf life of cut apples was extended to several weeks, especially when an initial atmosphere of 90.5% N(2) + 7% CO(2) + 2.5% O(2) and plastic pouches of 30 cm(3)/cm(2) x bar x 24 h were used. Under these conditions, a maximum 62% PPO activity depletion was observed. In all cases, the faster the initial PPO activity decays, the less the color changes. A fractional conversion first-order model was proposed for predicting color changes in minimally processed apples. Browning was better described through lightness (L) (k(L) = 0.017 - 0.07 day(-1)) and color difference (Delta E*) values (k(Delta E) = 0.015 - 0.073 day(-1)), which fitted the model with enough accuracy.     

高氧气调包装对不同品种冷却猪肉贮藏品质及持水性的影响

为了研究不同品种冷却猪肉在高氧气调包装贮藏过程中,蛋白氧化对猪肉品质及持水性的影响,试验以氟烷基因(NN)型杜长大三元杂交猪和不含NN基因型的三门峡黑猪为研究对象,分析了2个品种猪肉经高氧气调包装(80%O2+20%CO2),于(4±1)℃下贮藏过程中肌肉色泽、蛋白质氧化、水分分布、保水性以及肌肉微观结构的变化。结果表明,随着贮藏时间的延长(0~10 d),2个品种猪肉的肌原纤维蛋白羰基含量显著升高(P0.05),巯基含量显著降低(P0.05),表明猪肉肌原纤维蛋白的氧化程度随着贮藏时间的延长而加剧;肌原纤维蛋白发生持续性氧化,肌原纤维蛋白骨架的完整性遭到不同程度破坏,肌束膜破裂,纤维束间隙增大,结构疏松,保水性降低,不易流动水逐渐态变为自由水;与贮藏初始相比,第3天时杜长大三元杂交猪和三门峡黑猪的不易流动水均显著降低(P0.05),第5天杜长大三元杂交猪的自由水显著增加(P0.05),而黑猪的自由水在第10天时显著性增加(P0.05);贮藏5 d以上时,2个品种猪肉的蒸煮损失率均较对照组的蒸煮损失显著增大(P0.05);2个品种猪肉的L*值、a*值、b*值均呈现先增加再降低的趋势,L*值在第7天时达到最大值,a*值在第3天时达到最大值,杜长大三元杂交猪和黑猪的b*值分别在第5天和第7天时达到最大值;2个品种的猪肉经高氧气调包装,其色泽、蛋白质氧化、水分态变、保水性、微观结构等指标变化规律相似,表明高氧气调包装对2种猪肉的贮藏品质及持水性的影响效应具有一致性。研究结果为高氧气调包装冷却猪肉贮藏品质及汁液流失控制提供依据。     

Impact of blanching and packaging atmosphere on the formation of aroma compounds during long-term frozen storage of leek (Allium ampeloprasum Var. Bulga) slices.

The content of aroma compounds and the catalytic activity of lipoxygenase (LOX), alliinase, hydroperoxide lyase (HPL), and alcohol dehydrogenase (ADH) were analyzed in unblanched and blanched 15-mm leek slices packed in atmospheric air (21% O2) or 100% nitrogen (0% O2) three times during 12 months of frozen storage (12 M). The total amount of sulfur compounds and the total amount of aldehydes were greatly influenced by storage time, atmosphere, and blanching [concentration of sulfur compounds in fresh unblanched (UNB) slices = 1.35 mg/L, fresh blanched (B) slices = 1.09 mg/L, UNB 21% O2 12 M = 0.656 mg/L, UNB 0% O2 12 M = 2.11 mg/L, B 21% O2 12 M = 1.14 mg/L, B 0% O2 12 M = 1.59 mg/L]. B 0% O2 was closest to the original ratio between sulfur compounds and aldehydes after 12 months. The activities of HPL and alliinase were totally lost after 12 months, and ADH showed minimal activity, whereas LOX (UNB 0% O2) showed approximately 25% of the original activity. LOX was the most and HPL the least heat labile enzyme investigated.     

Impact of blanching and packaging atmosphere on the formation of aroma compounds during long-term frozen storage of leek (Allium ampeloprasum Var. Bulga) slices.

The content of aroma compounds and the catalytic activity of lipoxygenase (LOX), alliinase, hydroperoxide lyase (HPL), and alcohol dehydrogenase (ADH) were analyzed in unblanched and blanched 15-mm leek slices packed in atmospheric air (21% O2) or 100% nitrogen (0% O2) three times during 12 months of frozen storage (12 M). The total amount of sulfur compounds and the total amount of aldehydes were greatly influenced by storage time, atmosphere, and blanching [concentration of sulfur compounds in fresh unblanched (UNB) slices = 1.35 mg/L, fresh blanched (B) slices = 1.09 mg/L, UNB 21% O2 12 M = 0.656 mg/L, UNB 0% O2 12 M = 2.11 mg/L, B 21% O2 12 M = 1.14 mg/L, B 0% O2 12 M = 1.59 mg/L]. B 0% O2 was closest to the original ratio between sulfur compounds and aldehydes after 12 months. The activities of HPL and alliinase were totally lost after 12 months, and ADH showed minimal activity, whereas LOX (UNB 0% O2) showed approximately 25% of the original activity. LOX was the most and HPL the least heat labile enzyme investigated.