Non-vacuum Packaging Research Articles

Influence of protectant for encapsulation by freeze-drying and spray-drying techniques, and packaging environments on the stability of the probiotic Bifidobacterium animalis subsp. lactis strain KMP-H9-01 during storage

The process of drying probiotic bacteria to enhance their storage stability is important for the food industry. This study aimed to assess the efficacy of various drying techniques and food-grade protectants in preserving the viability of Bifidobacterium animalis subsp. lactis KMP H9-01 during drying and under prolonged storage conditions. Among the four protectants tested (skim milk, trehalose, sucrose, and maltodextrin), trehalose and skim milk at 5% (w/v) were selected for freeze- and spray-drying, each conducted at different temperatures. This evaluation encompasses survivability and the observation of the shelf life of probiotic powders. The results demonstrated that spray-drying at 160 °C/80 °C, with either skim milk or trehalose as a protectant, yielded the highest viable cell counts (>log 7 CFU/g) even after 6 months of storage at room temperature in the range of 25–30 °C, regardless of the use of vacuum and nonvacuum packaging. Notably, the calculated inactivation rate values (KRT) demonstrated remarkable stability, ranging from 5.36 × 10−2 to 5.82 × 10−2 day−1. Furthermore, the decimal reduction time (DRT) values predicted that a 90% reduction in probiotic cell number would require approximately 1.3 to 1.4 months at room temperature.

Estimation of shelf life for Ready-To-Eat sardines (RTE) using the Accelerated Shelf-Life Testing (ASLT) method

Ready-to-eat sardines (RTE) are ready-to-eat foods designed to satisfy the needs of people who don’t have time to cook. In order to maintain the quality of RTE products and have a longer shelf life, efforts should be made to maintain the quality of RTE products, one of which is the use of cold storage methods and packaging. The purpose of this study was to estimate the shelf life of RTE sardines using the accelerated method combined with the Arrhenius method. This study employs a completely randomised Design with two factors: packaging type (vacuum and non-vacuum packaging) and storage temperature (cold storage and freezing temperature). The parameters tested in this research include TPC (total plate count), organoleptic properties, fat content, and protein content. The estimated shelf life of ready-to-eat sardines (RTE) in this study shows that RTE fish has a shelf life of up to 558.96 days if stored at a freezing temperature and vacuum packed, and 313.29 days if stored at a refrigerated temperature and vacuum packed. While ready-to-eat sardines (RTE) have a shelf life if stored using pouch packaging of 514.83 days at freezing and 2945.13 days at refrigerated temperatures with the Arrhenius equation obtained, namely ln k = (13.436 – 3034.6) (1/T).

Improvement of Injera Shelf Life and Staling through Vacuum and Nonvacuum Polyethylene Packaging: Their Synergistic Effect with Chemical Preservative

The application of vacuum packaging (VP) and nonvacuum packaging (NP) of injera, with or without preservative added (sodium benzoate), has been studied for 15 days with the aim of determining their effect on the shelf-life and staling of injera. Samples were tested for microbial load analysis, moisture content (MC), pH, and color “L” value (lightness) determination, visible mold sign inspection, and sensory quality evaluation. Oxygen exclusion of the packaging methods and antimicrobial activities of preservative used, prolong the storage duration of injera without visible mold growth to more than 15 days; with VP (vacuum packaging), VP+ (vacuum packaging with preservative), and NP+ (nonvacuum packaging with preservative) treatments. Among these, VP+ had the least microbial load ( 5.3 ∗ 10 1 & 9.0 ∗ 10 1 bacterial & yeast and mold colony forming unit (cfu)/g, respectively). But it was least effective regarding staling as it had the least average scoring of MC, pH, and L value (60.96%, 3.33, and 45.92, respectively) and sensory acceptability, basically due to the crumbling effect of the packaging method used. Besides, NP + had a lower microbial load ( 7.5 ∗ 10 1 bacterial cfu/g and 9.0 ∗ 10 1 yeast and mold cfu/g). Despite VP and VP+, NP+ was a relatively effective method regarding sensory acceptability and staling as it had 62.73%, 3.32, and 48.70 average MC, pH, and L value, respectively. Generally, packaging methods and preservative used were found to have a significant effect ( P < 0.05 ) on microbial load, physico-chemical properties, and sensory attributes of injera. Moreover, it was proved that NP+ was the most effective method to improve the shelf life and staling of injera.

Study of Viability, Storage Stability, and Shelf Life of Probiotic Instant Coffee Lactiplantibacillus plantarum Subsp. plantarum Dad-13 in Vacuum and Nonvacuum Packaging at Different Storage Temperatures.

Probiotic coffee is an alternative to processed coffee that is preferred and can improve the balance of intestinal microflora so that it has a positive impact on health. Cell viability of probiotics may decrease during storage. Factors that can affect viability during storage are storage temperature, packaging, oxygen, and water activity. This study is aimed at evaluating the viability, storage stability, and shelf life of the probiotic instant coffee Lactiplantibacillus plantarum subsp. plantarum Dad-13 in vacuum and nonvacuum aluminium foil packaging and different storage temperatures. This study used a complete randomised design with three replicates of treatments. They were packaged using 90 μm thick aluminium foil in a vacuum and nonvacuum and stored at 4°C and 30°C for 50 days and 37°C for 15 days. Based on the literature, a temperature of 4°C can maintain the viability of probiotics for more than one month, the temperature commonly used to store dry products is room temperature (30°C), so longer storage (50 days) is tried. Meanwhile, to accelerate the prediction of quality degradation, extreme temperatures were used based on the literature that the viability of probiotics decreased drastically after being stored at 37°C for 7 days, then tried for longer storage (15 days). The evaluation of product was carried by sensory testing by comparing commercial instant coffee. The product has been tested for cell viability, water activity, and shelf life. The result showed that the colour attribute was significantly different for all formulations. The bitterness of probiotic instant coffee differed significantly from other formulations. The commercial instant coffee was preferred by panellist in terms of colour and bitterness. The aroma, sweetness, and overall attributes of all formulations were not significantly different. The cell viability in vacuum was higher than nonvacuum treatment, and it was higher in 4°C. However, cell viability for all treatments and during storage was still above 107 log CFU/g. Water activity in probiotic instant coffee with vacuum packaging is lower than in nonvacuum and stored at 4°C lower than in other temperatures. However, all treatments were still below 0.60. The shelf life of products reaches two years when they are stored in vacuum packaging at 4°C while a temperature of 30°C reaches 3 months. So, the panellists accepted probiotic instant coffee, vacuum packaging, and low temperature could maintain viability, stability, and longer shelf life.

Vacuum packaging improved inactivation efficacy of moderate dry heat for decontamination of Salmonella on almond kernels

The goal of this study was to develop dry heat processing conditions that could achieve a >5-log reduction of Salmonella with minimal negative impact on almond quality. The effects of almond's water activity (aw) levels and packaging methods on Salmonella inactivation by dry heat were determined. Almonds were dip-inoculated in a four-strain Salmonella cocktail and conditioned to aw of 0.43, 0.33, 0.23, and 0.20. The inoculated almonds were then placed in vacuum-sealed mylar bags (vacuum packaging), ambient-sealed glass tubes (non-vacuum packaging), and petri dishes without covers (no packaging). The packaged and un-packaged almonds were treated by dry heat with 13 % relative humidity at 73 °C. Vacuum packaging in general achieved slightly better (in some cases significantly better (p < 0.05)) or similar inactivation effect on Salmonella than non-vacuum packaging. Both vacuum and non-vacuum packaging methods achieved much greater Salmonella inactivation than the no packaging method. For example, a 4-h treatment at 73 °C reduced Salmonella on almonds with aw of 0.43 by 5.1-, 4.4-, and 1.3-log for mylar bag, tube, and petri dish, respectively. Higher aw levels resulted in better inactivation of Salmonella. To achieve a >4-log reduction of Salmonella on almonds packaged in mylar bags, 3-, 6-, 8-, and 8-h of heat treatment were needed for almonds with aw values of 0.43, 0.33, 0.23 and 0.20, respectively. Vacuum packaging in combination with a 4-h heat treatment of almonds with initial aw of 0.43 or 8-h heat treatment of almonds with initial aw of 0.33 could achieved a ≥5-log reduction of Salmonella. Those two combinations resulted in very little weight loss (≤0.05 %), insignificant color change (∆E ≤ 1.26), and unnoticeable change in visual appearance of almonds, demonstrating that they could be potentially used for raw almond pasteurization.

Olive oil oleogels as strategy to confer nutritional advantages to burgers

The effect of bovine back fat replacement by oleogels containing pork skin and olive oil on the oxidative stability, physicochemical, technological, nutritional, and sensory parameters of burgers was evaluated. Four different hamburger (H) were manufactured: with 90 % of lean beef and 10 % of bovine back fat (control, HC), or with 10 % of pork skin/water/virgin olive oil (HVOO), stripped olive oil added of an olive leaf extract (HESOO) or stripped olive oil (HSOO) oleogels, at 20:60:20 ratio. Physical-chemical stability was assessed after storage for 7 days at 4 °C and for 90 days at −20 °C, under non-vacuum and vacuum packaging.A reduction in the fat content by 80 % and in the energy content by 35 %, an increase in the protein content by 15 % and a better fatty acid profile were achieved in the oleogel containing burgers. After processing at 180 °C (grill), hardness, chewiness, sensory parameters and overall acceptability were high and comparable to control. All burgers were oxidative stable during 7 days at 4 °C. After storage for 90 days at −20 °C, only HSOO samples stored under non-vacuum packaging were oxidized. The antioxidant content in samples HVOO and HESOO efficiently prevented the oxidation of these samples.

Estimating the Shelf Life of Oyster Mushroom Rendang packed with Vacuum or Non-Vacuum technique by the Application of the Arrhenius Methods

Rendang is a famous traditional food from West Sumatra, Indonesia. Oyster mushroom rendang is made from oyster mushrooms. Based on its composition, the degradation of fat is its critical point during storage. Proper packaging can extend the shelf life of oyster mushroom rendang. The purpose of this study was to determine the shelf life of oyster mushroom rendang that pack in vacuum and no vacuum packaging using the Accelerated Shelf-Life Testing (ASLT) method according to the Arrhenius equation. As a result, at a temperature of 25°C, oyster mushroom rendang packaged in vacuum packaging has a shelf life of 613 days and in non-vacuum packaging has a shelf life of 43 days.

An effective heat dissipation strategy improving efficiency and thermal stability of phosphor-in-glass for high-power WLEDs

Phosphor-in-glass (PiG) is one of the most important spectral converters to overcome thermal effect in high-power white light-emitting diodes (LEDs). The Al2O3–SiO2–B2O3–ZnO–Na2O–Li2O glass was designed and sintered with Y3Al5O12:Ce3+ (YAG: Ce) phosphors at the low temperature of 650 °C to obtain YAG: Ce-PiG. The optimized YAG: Ce-PiG shows the white light of the luminous efficiency (LE), correlated color temperature (CCT) and chromaticity coordinate (CIE) of 177.5 lm/W, 6410 K and (0.31,0.34), respectively. The white LEDs (WLED) were fabricated by coupling the YAG: Ce-PiG with a blue light emitting chip, and the correlation between the luminescence properties, the thickness of PiG and the ratio of phosphors was investigated. More importantly, the WLEDs of a maximum luminous efficiency can reach up to 199.5 lm/W with the thickness of 0.35 mm. In addition, a structure with vacuum packaging technique based on the WLEDs lighting combined with sapphire as substrate was fabricated, which can effectively reduce the heat accumulation during the working process of WLEDs. Compared with normal non-vacuum packaging, the working temperature of WLEDs was reduced by about 35%, from 359.2 to 232.2 °C, with the novel vacuum packaging technique under 30W high-power chip and the luminous performance can still be maintained at 94.7%. In a word, the prepared YAG: Ce-PiG exhibits a great potential for application in high-power solid-state WLEDs.

Germination and Water Content of Cocoa Seeds After Storage Treatments

The challenge of providing cocoa seeds is the characteristic of recalcitrant seed, thus requiring storage techniques that can slow down the decline in seed viability in an effort to manage the distribution of cocoa seeds which depend to the time of demand and harvest. The research aimed to study the effect ofpackaging method for storage of cocoa seeds; the effect of shelf life and temperature to germination and water content of seeds, and the stability of seed germination at different age and storage temperature. The research was conducted at Kaliwining Experimental Station, Indonesian Coffee and Cocoa Research Institute, Jember, East Java. The research used complete randomized design with research design using split plot. The treatments consisted of packaging methods, storage temperature and storage life. Packaging methods consisted of two methods, i.e. vacuum methods and non vacuum methods. Storage temperature consisted of three treatments, i.e. 15OC, 25OC and 30OC. both of packaging and temperature treatments were stored at four shelf life treatment included 1 week, 2 weeks, 3 weeks, and 4 weeks. Each treatment was repeated with three replications and each treatment per replication consisted of 50 seeds. Data analysis used SAS 9.0 and stability analysis used R program and PB Tool. Water content of seeds, germination of seeds and number of seedy seeds were observed. The results showed that type of packaging and storage temperature effect to germination of cocoa seeds but did not effect to seeds water content. Storage of cocoa seeds by non-vacuum packaging showed a higher of germination compared to vacuum packaging in all temperature treatments. Storage with non vacuum packaging at a temperature 25OC showed a germination more than 85% for 2 weeks of shelf life, while storage of cocoa seeds at a temperature of 30OC had a germination of more than 85% for only 1 week shelf life. Storage of cocoa seed at 15OC showed the lowest of germination at treatment. Storage treatments did not show effect on water content of cocoa seeds.

Effect of Vacuum and Non-Vacuum Packaging on Total Phenolic Content of Encapsulated &lt;i&gt;Orthosiphon&lt;/i&gt; &lt;i&gt;stamineus&lt;/i&gt; Spray-Dried Powder during Storage

The experiment was conducted to determine the effects of vacuum and non-vacuum packaging on the total phenolic content of encapsulated O. stamineus spray-dried powder when stored under different temperatures (10 and 25 °C) for 4 weeks of storage period. The total phenolic compound was measured using the Folin-Ciocalteu method and was analyzed using UV/VIS spectrophotometer. The results showed that both vacuum and non-vacuum packing affected the consistency of capsulated O. stamineus spray-dried powder during storage. The total phenolic content of the samples significantly increased for both vacuum and non-vacuum packaging when stored at 10 °C. However, the total phenolic content of the samples for both vacuum and non-vacuum packaging decreased after 2 weeks of the storage period when the samples stored at room temperature, 25 °C. Thus, it is suggested to keep the encapsulated O. stamineus spray-dried powder under low temperature (10 ˚) with vacuum packaging to sustain the medicinal properties quality and to prolong the shelf-life of the encapsulated products.

Effect of Edible Coatings Based on Oxidized Cassava Starch on Color and Textural Properties of Minimally Processed Yam

The effect of the edible coating of oxidized cassava starch along with two packaging conditions on color and textural properties of minimally processed yam was evaluated. The coating suspensions were formulated with an oxidized cassava starch (3 and 5%), ascorbic acid (0.5 and 1%), carnauba wax (0.1 and 0.2%), glycerol (1%), Tween 80 (0.1%) and applied to yam cubes. Samples were packaged in two different conditions (vacuum and non-vacuum). Changes in color and texture properties were measured during 42 days storage at 25°C. A non-vacuum packaging and low wax concentrations increased browning index (61.6%), while the vacuum packaging and this same wax concentration decreased browning index (47.2%). Low acid and high wax concentrations increased 1.52% lightness. A non-vacuum packing and a decrease in wax concentration produces a decrease in hardness (6.37%) of yam while a vacuum packing this same change in wax concentration causes an increase in the hardness (1.51%). In synthesis, a vacuum packing and coatings with 5% of oxidized cassava starch, 0.1% wax and 0.5% of acid maintains the color and hardness of minimally processed yam during storage.

Effect of Edible Coatings Based on Oxidized Cassava Starch and Vacuum Packaging on Physicochemical Properties of Minimally Processed Yam

This research studied the effect of edible coatings based on oxidized cassava starch and two conditions of packaging (vacuum and non-vacuum) on physicochemical properties of minimally processed yam. A factorial arrangement of 24 was applied to the following factors: oxidized starch of yucca (3 and 5%), ascorbic acid (0.5 and 1%), carnauba wax (0.1 and 0.2%), determining the physicochemical properties of minimally processed yam for 42 days. High concentrations of acid and wax decreased the pH and the acidity of yam by 10.2 and 5.25%, respectively. A vacuum packaging and high levels of wax increased the acidity by 10.8% and a non-vacuum packaging with the same level of wax deceased it by 5.76%. The moisture content increased by 3.24% and the total solids decreased by 2.48% in a vacuum packaging in low concentrations of wax, due to the weak barrier caused by wax at low concentrations. Weight loss increased with the time of storage, as a cut produces cells breakage which in turn, results in a greater moisture loss. Finally, 0.5% of acid and 0.1% of wax in the coating maintain the physicochemical properties of yam.

Microbial shelf stability assessment of osmotically dehydrated smoky apples

The infusion of Refined Liquid Smoke (RLS) during osmotic dehydration in apples slices was performed and its effect on some selected quality attributes (color, texture, and microbial load) of resulting apples was evaluated over a storage period under vacuum and non-vacuum packaging. Prior to hot air drying at 74 °C, fresh apple slices were pretreated via osmotic dehydration using either 42% w/w sugar solution or 42% w/w sugar solution with 1% food grade refined liquid smoke (RLS). The quality attributes were measured at room temperature during a storage period of five months. For control, quality attributes of convectively dried apples with no osmotic dehydration pretreatment were used. The result showed that dried apple slices pretreated in pure sugar solution retain the color of fruit better than untreated dried samples, while samples infused with RLS showed a characteristic brown coloration. Additionally, RLS infused dried apples showed better textural properties when compared with the control. In all samples, significant microbial reduction (below 5 log CFU/g) was recorded throughout the storage period. However, RLS infused dried apples showed the highest microbial growth reduction and the control showed the worst microbial growth reduction in a non-vacuum package.

Calidad y cambios microbiológicos en calabaza mínimamente procesada y empacada en polietileno de baja densidad

La calabaza (Cucurbita moschata) mínimamente procesada tiene un potencial considerable para crear nuevas oportunidades en el mercado de valor agregado en Puerto Rico. El objetivo de este trabajo fue evaluar la calidad y microbiología de la calabaza tropical mínimamente procesada empacada en bolsas de polietileno de baja densidad (LDPE, por sus siglas en inglés) y almacenada durante 20 días. Pedazos de 2 cm3 de dos cultivares de calabaza ('Taina Dorada' y 'Soler') fueron tratados por inmersión con una solución antimicrobiana que contenía ácido cítrico (0.2%) y benzoato de sodio (0.1%) durante 3 min, centrifugados en una hilandera de ensaladas, empacados en bolsas de LDPE, sellados al vacío y sin vacío, y almacenados a 4° C ± 2 durante un período de 20 días. El tiempo de almacenamiento tuvo un efecto mínimo sobre las características químicas y físicas de los pedazos de calabaza. El contenido de O2 en los empaques sellados sin vacío disminuyó, mientras que el contenido de CO2 tuvo un incremento en las primeras 72 horas de almacenamiento. Los jurados del panel sensorial determinaron que la calabaza almacenada por 20 días mantiene una calidad aceptable. El producto mínimamente procesado tratado con una solución antimicrobial, empacado en bolsas de LDPE (selladas al vacío o sin vacío) y almacenado por 20 días a 4° C ± 2 presentó niveles microbiológicos seguros y una calidad aceptable por el consumidor.

Optimization of packaging and storage conditions of a freeze-driedPantoea agglomeransformulation for controlling postharvest diseases in fruit

This study aimed to evaluate different packaging strategies to extend the shelf life of a freeze-dried formulation of the biocontrol agent Pantoea agglomerans strain CPA-2. Different materials and atmosphere packaging conditions (vacuum and air) were analysed on formulated P. agglomerans cells stored at 25, 5 and -20°C. Results showed the viability of CPA-2 cells stored at 5 or -20°C was significantly higher than when stored at 25°C. The highest viabilities were observed with the plastic material designated as Bottle 1, in nonvacuum packaging in all storage temperatures: 50% after 3 months at 25°C, 100% after 8 months at 5°C and 100 and 74% after 12 and 18 months, respectively, at -20°C; the final concentration was 10(12) CFU g(-1), a good concentration for a commercial product. The efficacy to control blue and green mould on apples and oranges, respectively, of these packed and stored cells was similar to fresh CPA-2 cells. This work showed a suitable packaging strategy for a freeze-dried formulation of the CPA-2, providing a good shelf life and efficacy against the major postharvest diseases of apples and citrus based on a plastic bottle stored at cold or frozen storage conditions. The last phase of the commercial development process for biocontrol agents is presented in this work. A bacterium-based product that ensures the efficacy, stability and easy application of the antagonist to control postharvest fungal diseases on fruit was successfully obtained.

Effects of temperature, packaging and electron beam irradiation processing conditions on the property behaviour of Poly (ether-block-amide) blends

The radiation stability of Poly (ether-block-amide) (PEBA) blended with a multifunctional phenolic antioxidant and a hindered amide light stabiliser was examined under various temperatures, packaging and electron beam processing conditions. FTIR revealed that there were slight alterations to the PEBA before irradiation; however, these became more pronounced following irradiation. The effect of varying the temperature, packaging and processing conditions on the resultant PEBA properties was apparent. For example, rheology demonstrated that the structural properties could be enhanced by manipulating the aforementioned criteria. Mechanical testing exhibited less radiation resistance when the PEBA samples were vacuum packed and exposed to irradiation. MFI and AFM confirmed that the melting strength and surface topography could be reduced/increased depending on the conditions employed. From this study it was concluded that virgin PEBA submerged in dry ice with non-vacuum packaging during the irradiation process, provided excellent radiation resistance (20.9% improvement) in contrast to the traditional method.

신선편이 단호박 원료의 후숙기간 및 가공 후 포장방법에 따른 저장 중 품질변화

This study was conducted in order to evaluate the effect of postharvest ripening periods and packaging methods on maintaining the quality of fresh-cut winter squash. Winter squash (var. Bouchang) was ripened at 22°C for 1 or 2 weeks after harvest. The samples were washed in tap water, sanitized in 100 μL/L chlorine water, peeled, and cut into 16 parts. Samples were then vacuum packaged or non-vacuum packaged in 80 μm nylon/polyethylene (Ny/PE) films and stored at 5°C for 21 days. Results indicated that different postharvest ripening periods affected gas concentration, firmness, off-odor development, color, and overall quality of fresh-cut winter squash. Samples treated with 2-week ripening periods maintained quality with higher redness value and soluble solid content (SSC) and lower CO2 concentration and off-odor development compared to samples treated with a 1-week ripening period. Non vacuum packaging was effective in increasing visual quality and reducing off-odor development. A combination treatment of 2-week ripening periods and non-vacuum packaging maintained good quality with the lowest off-odor development and the highest visual quality scores at the end of the storage period.

Structural-Acoustic Coupling Effects on the Non-Vacuum Packaging Vibratory Cylinder Gyroscope

The resonant shells of vibratory cylinder gyroscopes are commonly packaged in metallic caps. In order to lower the production cost, a portion of vibratory cylinder gyroscopes do not employ vacuum packaging. However, under non-vacuum packaging conditions there can be internal acoustic noise leading to considerable acoustic pressure which is exerted on the resonant shell. Based on the theory of the structural-acoustic coupling, the dynamical behavior of the resonant shell under acoustic pressure is presented in this paper. A finite element (FE) model is introduced to quantitatively analyze the effect of the structural-acoustic coupling. Several main factors, such as sealing cap sizes and degree of vacuum which directly affect the vibration of the resonant shell, are studied. The results indicate that the vibration amplitude and the operating frequency of the resonant shell will be changed when the effect of structural-acoustic coupling is taken into account. In addition, an experiment was set up to study the effect of structural-acoustic coupling on the sensitivity of the gyroscope. A 32.4 mV/°/s increase of the scale factor and a 6.2 Hz variation of the operating frequency were observed when the radial gap size between the resonant shell and the sealing cap was changed from 0.5 mm to 20 mm.

The effect of different packaging methods on the formation of biogenic amines and organic acids in Kashar cheese

The effects of packaging methods (nonvacuum and vacuum) on biogenic amines (cadaverine, putrescine, tyramine, tryptamine, phenylethylamine, and histamine) and organic acids (citric, lactic, formic, acetic, propionic, and butyric) during storage for 180 d at 4°C were investigated in Kashar cheese. Dry matter, titratable acidity, total nitrogen, water-soluble nitrogen, trichloroacetic acid-soluble nitrogen, phosphotungstic acid-soluble nitrogen, free amino group (proteolysis), pH, fat, and acid degree value were also determined. Storage period had a significant effect on all of the biogenic amines. When compared with vacuum packaging, nonvacuum packaging resulted in no large differences among the amounts of biogenic amines. Vacuum-packaged cheeses had more lactic, formic, acetic, and butyric acids than did cheeses packaged without vacuum. Water-soluble nitrogen, trichloroacetic acid-soluble nitrogen, phosphotungstic acid-soluble nitrogen, proteolysis, pH, and acid degree values of the cheese samples increased continuously until the end of the ripening in all the samples. No significant change was observed in total nitrogen, dry matter, or fat content within the ripening period, whereas titratable acidity values changed significantly in vacuum-packaged cheese and decreased slightly in the non-vacuum-packaged cheeses. The results of this study showed that storage period and packaging method had significant effects on the quality of Kashar cheese.

Physicochemical changes in ω − 3-enhanced farmed rainbow trout ( Oncorhynchus mykiss) muscle during refrigerated storage

Physicochemical changes of ω − 3-enhanced farmed rainbow trout ( Oncorhynchus mykiss) fillets developed by dietary modification with flaxseed oil and α-tocopheryl acetate (α-TA) were determined during storage at 2 °C. Trout were fed experimental diets for 120 days followed by processing to obtain boneless skinless fillets. The dietary modification increased concentration of total ω − 3 fatty acids in the fillets, which enhanced chances for lipid oxidation during storage. The fillets were vacuum or non-vacuum packed and stored at 2 °C for 10 or 12 days. Dietary α-TA resulted in higher ( P < 0.05) concentration of α-tocopherol in fillets during storage; however, it did not retard ( P > 0.05) lipid oxidation. Vacuum packaging resulted in much lower ( P < 0.05) TBARS and higher ( P < 0.05) retention of α-tocopherol during storage than non-vacuum packaging. However, α-tocopherol unlike vacuum packaging better protected ω − 3 FA in the fillets during storage.