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The storage duration of fresh meat products is a contributing factor leading to increased waste and loss at the retail counter. Losses of fresh pork can be linked to packaging methods that do not protect the attributes of color, taste, and odors consumers use in determining wholesome meat. Boneless pork loins (N = 63) were fabricated into 2.54-cm-thick chops and assigned to one of three vacuum treatments (VacA, VacB, VacC) or a fourth polyvinyl chloride overwrap (PVC) treatment to assess objective fresh color, cook loss, Warner-Bratzler shear force (WBSF), and lipid oxidation. Pork chops (n = 882) were evaluated at 5-day intervals (D 0, 5, 10, 15) in a randomized complete block design. Pork chop surface color was lighter (L*; p < 0.0001) when stored in a vacuum compared to PVC-packaged loin chops, regardless of storage duration. Redness (a*) values were greater (p < 0.0001) for loin chops stored in PVC than all other vacuum packaging treatments throughout the entire 15-day display period. Relative values for chroma on PVC-packaged loin chops were greater (p < 0.0001) throughout the simulated retail display period. An interaction of day and packaging treatment (p < 0.0343) occurred for WBSF. Lipid oxidation for pork chops packaged using PVC was significantly greater (p < 0.0001) from Day 10 through the completion of the storage period. Results indicate that vacuum packaging limits the deterioration of fresh pork loin chops, whereas traditional overwrapping expedites the color and lipid oxidation during refrigerated storage.

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The freshness of Atlantic salmon is influenced mainly by tissue metabolism, which in turn is affected by storage time and conditions. The alterations in taste profiles and nutritional values of salmon when packaged using vacuum methods have not been fully understood, and the factors contributing to these changes require further research. In this work, the extraction method for flavor nutrients from salmon was optimized via the Plackett-Burman (PB) test. A sensitive and rapid targeted metabolomics method for the simultaneous determination of 34 nutrients was successfully established via ultra-performance liquid chromatography-triple quadrupole/linear ion trap composite mass spectrometry (UHPLC-QTRAP/MS), and various nutritional compositions during storage at 0 °C under different vacuum conditions (0 kPa or -90 kPa) for 4 and 8 days were analyzed. Results showed that storage time had a significant effect on salmon metabolism. The total amino acids decreased by 62.95% and 65.89% at 0 kPa and -90 kPa, respectively. Notably, a marked reduction in histidine after 8 days at -90 kPa may have diminished bitterness, while decreased levels of umami-tasting amino acids like glutamine and aspartic acid affected the overall flavor profile. Overall, the packaging conditions at 0 °C and 0 kPa were more suitable for the preservation of most nutrients in salmon. Pathway enrichment analysis revealed that the reduction in substances was mainly related to the alanine, aspartate, and glutamate metabolism pathways. Alanine, inosine, and histidine, whose levels changed significantly, can bind to the typical umami taste receptor TIR1/TIR3 and can be biomarkers to monitor and determine the freshness or spoilage of salmon after 4-8 days of storage. This study revealed the changes in small-molecule nutrients in salmon during storage under different packaging conditions, which provides a reference for the packaging preservation technology of fresh salmon and new ideas for the evaluation of salmon quality and determination of freshness.

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Storing ground beef at frozen temperatures prior to refrigerated display when using thermoforming vacuum packaging is not a common manufacturing practice. However, limited data on thermoforming packaging film and its interaction with meat quality suggests that more information is needed. The current study aimed to identify the influences of thermoforming packaging on the surface color and lipid oxidation of ground beef. Ground beef was portioned into 454 g bricks and packaged into one of three thermoforming films: T1 (150 µ polyethylene/EVOH/polyethylene coextrusion), T2 (175 µ polyethylene /EVOH/polyethylene coextrusion), and T3 (200 µ polyethylene/EVOH/polyethylene coextrusion), stored for 21 days at -20.83 °C (±1.50 °C), and displayed for 42 days at 3.0 °C ± 1.5 °C. There were no statistical differences for the packaging treatment of lipid oxidation (p = 0.0744), but oxidation increased throughout storage day (p < 0.0001). The main effects of treatment and day resulted in altered (p < 0.05) surface lightness (L*), redness (a*), yellowness, hue angle (°), red-to-brown (RTB), and relative myoglobin for met-myoglobin (MET), deoxymyoglobin (DMB), and oxymyoglobin (OMB). Surprisingly, there was an interaction between treatment and day for the calculated relative values of chroma (p = 0.0321), Delta E (p = 0.0155), and the ratio of a*:b* (p < 0.0001). These results indicate that thermoforming vacuum packaging can reduce the rate of deterioration that occurs to ground beef color and the rate of oxidation.

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Using sous-vide technology in combination with essential oils offers the potential to extend the preservation of food items while preserving their original quality. This method aligns with the growing consumer demand for safer and healthier food production practices. This study aimed to assess the suitability of minimal processing of game meat and the effectiveness of vacuum packaging in combination with Piper nigrum essential oil (PNEO) treatment to preserve red deer meat samples inoculated with Listeria monocytogenes. Microbial analyses, including total viable count (TVC) for 48 h at 30 °C, coliform bacteria (CB) for 24 h at 37 °C, and L. monocytogenes count for 24 h at 37 °C, were conducted. The cooking temperature of the sous-vide was from 50 to 65 °C and the cooking time from 5 to 20 min. Additionally, the study monitored the representation of microorganism species identified through mass spectrometry. The microbiological quality of red deer meat processed using the sous-vide method was monitored over 14 days of storage at 4 °C. The results indicated that the TVC, CB, and L. monocytogenes counts decreased with the temperature and processing time of the sous-vide method. The lowest counts of individual microorganism groups were observed in samples treated with 1% PNEO. The analysis revealed that PNEO, in combination with the sous-vide method, effectively reduced L. monocytogenes counts and extended the shelf life of red deer meat. Kocuria salsicia, Pseudomonas taetrolens, and Pseudomonas fragi were the most frequently isolated microorganism species during the 14-day period of red deer meat storage prepared using the sous-vide method.

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This paper introduces a cost-effective, high-performance approach to achieving wafer level vacuum packaging (WLVP) for MEMS-based uncooled infrared sensors. Reliable and hermetic packages for MEMS devices are achieved using a cap wafer that is formed using two silicon wafers, where one wafer has precise grating/moth-eye structures on both sides of a double-sided polished wafer for improved transmission of over 80% in the long-wave infrared (LWIR) wavelength region without the need for an AR coating, while the other wafer is used to form a cavity. The two wafers are bonded using Au-In transient liquid phase (TLP) bonding at low temperature to form the cap wafer, which is then bondelectrical and Electronics d to the sensor wafer using glass frit bonding at high temperature to activate the getter inside the cavity region. The bond quality is assessed using three methods, including He-leak tests, cap deflection, and Pirani vacuum gauges. Hermeticity is confirmed through He-leak tests according to MIL-STD 883, yielding values as low as 0.1 × 10-9 atm·cc/s. The average shear strength is measured as 23.38 MPa. The package pressure varies from 133-533 Pa without the getter usage to as low as 0.13 Pa with the getter usage.

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The packaging system is one of the factors influencing the preservation of the nutritional value, microbiological safety, and sensory attributes of meat. The study investigated changes in physicochemical and microbiological properties taking place during 15-day refrigerated storage of two calf muscles, the longissimus lumborum (LL) and semitendinosus (ST), packaged in three systems, respectively, vacuum packing (VP), modified atmosphere packaging (MAP, 80% O2 + 20% CO2), and a combined system (VP + MAP, 8 d in VP followed by 7 d in MAP). LL and ST stored in VP had significantly lower levels of lipid oxidation, higher α-tocopherol content, and higher instrumentally measured tenderness in comparison with the samples stored in MAP. On the other hand, the MAP samples had lower purge loss at 5 and 15 days, a higher proportion of oxymyoglobin up to 10 days of storage, and a better microbiological status. Calf muscle samples stored in the VP + MAP system had intermediate values for TBARS and α-tocopherol content and at the same time were the most tender and had the lowest counts of Pseudomonas and Enterobacteriaceae bacteria at 15 days. All packaging systems ensured relatively good quality of veal characteristics up to the last day of storage. However, for MAP at 15 days of storage, unfavourable changes in colour (a high level of metmyoglobin and a decrease in oxymyoglobin, redness and R630/580 ratio) and in the lipid fraction (a high TBARS value and a significant decrease in α-tocopherol content) were observed.

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Fish fillets are highly susceptible to spoilage, with Pseudomonas spp. bacteria being among the main culprits. To maintain products' quality and safety, it is important to control the load of these microorganisms and understand their growth potential in fish fillets. However, setting up challenge tests might be hard due to the difficulty of differentiating intentionally inoculated bacteria from those already present on the fillets. To overcome this obstacle, a pilot study using Pseudomonas aeruginosa, a clinically significant bacterial species that is rare in food, was conducted. Vacuum-packed Northern cod, salmon, and plaice fish fillets were experimentally inoculated and subjected to trials at both refrigeration (4 °C) and thermal abuse temperatures (from +4 °C to +6 °C and then to +8 °C). The results showed that the growth potential of Pseudomonas aeruginosa in all the fish fillets was less than 0.5 Log10 CFU/g. This confirms that vacuum packaging could reduce the multiplication of Pseudomonas spp. in the fish fillets and underlines as it is crucial to have fish fillets containing initial loads of Pseudomonas between 104-105 CFU/g or lower at the beginning of the shelf life in order to control the deterioration rate of the product. This study provides a basis for developing further challenge tests for Pseudomonas spp. in the fish industry and highlights the importance of controlling initial loads of Pseudomonas to prevent product deterioration during the shelf life.

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BACKGROUND: Glasswort represents a novel alternative to KCl for replacing sodium in meat products. To evaluate the effects of Na reduction on the quality changes of a traditional dry cured belly due to storage, fresh bellies were dry-salted with 2% NaCl (BCON), with 2% of a mixture containing 50% NaCl and 50% KCl (BKCl) or with 1% of a mixture of 90% NaCl and 10% powdered glasswort (BGW), dry-cured, sliced, vacuum packaged and stored under refrigeration for 60 days. RESULTS: The BKCl and BGW bellies were lower in sodium by one-third to one-half compared to BCON (with 1.6 g Na/100 g). Neither BKCl, nor BGW significantly differed from BCON in free fatty acids (FFA) before and after storage, whereas BGW showed almost twice as much 2-methylbutanal content as BCON. All bellies showed microbiological stability during storage. Micrococcaceae was the most abundant microbial group with values of 105 to 106 colony-forming units g-1. The BGW presented higher Micrococcaceae counts (approximately one log unit) but lower microbial biodiversity than BCON. CONCLUSION: The two alternative dry salting methods reduced the sodium content in bellies, at the same time as ensuring chemical and microbiological stability during refrigerated vacuum storage. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

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In recent years, the presence and migration of PAEs in packaging materials and consumer products has become a serious concern. Based on this concern, the aim of our study is to determine the possible migration potential and speed of PAEs in benthic fish stored in vacuum packaging, as well as to monitor the storage time and type as well as polyethylene (PE) polymer detection.As a result of the analysis performed by µ-Raman spectroscopy, 1 microplastic (MP) of 6 µm in size was determined on the 30th day of storage in whiting fish muscle and the polymer type was found to be Polyethylene (PE) (low density polyethylene: LDPE). Depending on the storage time of the packaging used in the vacuum packaging process, it has been determined that its chemical composition is affected by temperature and different types of polymers are formed. 10 types of PAEs were identified in the packaging material and stored flesh fish: DIBP, DBP, DPENP, DHEXP, BBP, DEHP, DCHP, DNOP, DINP and DDP. While the most dominant PAEs in the packaging material were determined as DEHP, the most dominant PAEs in fish meat were recorded as BBP and the lowest as DMP. The findings provide a motivating model for monitoring the presence and migration of PAEs in foods, while filling an important gap in maintaining a safe food chain.

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By investigating wet and dry age-related ripening of beef, Pseudomonas strains V3/3/4/13T and V3/K/3/5T were isolated. Strain V3/3/4/13T exhibited more than 99 % 16S rRNA gene-based similarity to Pseudomonas fragi and other members of this group, while isolate V3/K/3/5T was very close to Pseudomonas veronii and a number of relatives within the Pseudomonas fluorescens group. Additional comparisons of complete rpoB sequences and draft genomes allowed us to place isolate V3/3/4/13T close to Pseudomonas deceptionensis DSM 26521T. In the case of V3/K/3/5T the closest relative was P. veronii DSM 11331T. Average nucleotide identity (ANIb) and digital DNA-DNA hybridization (dDDH) values calculated from the draft genomes of V3/3/4/13T and P. deceptionensis DSM 26521T were 88.5 and 39.8 %, respectively. For V3/K/3/5T and its closest relative P. veronii DSM 11331T, the ANIb value was 95.1 % and the dDDH value was 60.7 %. The DNA G+C contents of V3/3/4/13T and V3/K/3/5T were 57.4 and 60.8 mol%, respectively. Predominant fatty acids were C16 : 0, C18 : 1 ω7c, C17 : 0 cyclo and summed feature C16 : 1 ω7ct/C15 : 0 iso 2OH. The main respiratory quinones were Q9, with minor proportions of Q8 and, in the case of V3/K/3/5T, additional Q10. The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and, in the case of V3/K/3/5T, additional phosphatidylcholine. Based on the combined data, isolates V3/3/4/13T and V3/K/3/5T should be considered as representatives of two novel Pseudomonas species. The type strain of the newly proposed Pseudomonas kulmbachensis sp. nov. is V3/3/4/13T (=DSM 113654T=LMG 32520T), a second strain belonging to the same species is FLM 004-28 (=DSM 113604=LMG 32521); the type strain for the newly proposed Pseudomonas paraveronii sp. nov. is V3/K/3/5T (=DSM 113573T=LMG 32518T) with a second isolate FLM 11 (=DSM 113572=LMG 32519).

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The aim of this study was to investigate the antimicrobial effect of marination, natural antimicrobials, and packaging on the microbial population of chicken tawook during storage at 4°C. Chicken meat was cut into 10 g cubes and marinated. The chicken was then mixed individually with 0.5% or 1% (w/v) vanillin (VA), ß-resorcylic acid (BR), or eugenol (EU), and stored under aerobic (AP) or vacuum (VP) packing at 4°C for 7 d. The marinade decreased microbial growth as monitored by total plate count, yeast and mold, lactic acid bacteria, and Pseudomonas spp. by about 1 log cfu/g under AP. The combination of marinade and antimicrobials under AP and VP decreased growth of spoilage-causing microorganisms by 1.5 to 4.8 and 2.3 to 4.6 log cfu/g, respectively. Change in pH in VP meat was less than 0.5 in all treated samples including the control. Marination decreased the lightness of the meat (L*) and significantly (p < 0.05) increased the redness (A*) and yellowness (B*). Overall acceptability was highest for marinated samples with 0.5% BR.

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@#Keropok lekor is a fish-based snack and traditional food originating from the East Coast of Peninsular Malaysia, especially in Terengganu. This study was conducted to identify the ingredients and packaging used in the manufacturing of keropok lekor by entrepreneurs in Selangor. This study is a qualitative study that requires in-depth interviews. The Nutritionist Pro application was used to determine the nutrients in keropok lekor. The sampling method for this study is purposive sampling and involves five keropok lekor operators around Selangor. The ingredients used in making keropok lekor are salt, fish filling (fringescale sardine), baking powder, monosodium glutamate (MSG), margarine, and sweet potato flour. Through this study, it was found that the main source of sodium in keropok lekor is salt. For keropok lekor packaging, all keropok lekor operators use the same packaging method, which is vacuum packaging. In addition, the majority of keropok lekor operators (80%) have been introduced to Modified Atmosphere Packaging (MAP). The results of the study show that the average sodium content in keropok lekor is 372.11mg/100g and is categorized as medium-level sodium. Although the majority of keropok lekor operators have been introduced to MAP packaging, further research needs to be conducted to find out whether keropok lekor operators have renewed their packaging methods or vice versa. In conclusion, based on the findings, the content of sodium in the manufacturing of keropok lekor in Selangor is still under control. The results of this study can be used to help the government monitor the sodium content found in keropok lekor around Selangor.

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Ice glazing containing 0.3 % D-sodium erythorbate (DSE), combined with vacuum packaging, was used as a method to maintain the quality of large yellow croaker during frozen storage. This study aimed to assess various aspects, including water properties (water holding capacity and moisture distribution), protein-related characteristics (secondary and tertiary structure of myofibrillar protein), freshness indicators (K value and total volatile base nitrogen (TVB-N)), and non-volatile flavor compounds (free amino acids (FAAs) and nucleotides) in samples stored for 300 days at -23 °C. The results showed that vacuum packaging had a significant inhibitory effect on the growth of ice crystal. Notably, it successfully maintained the cross-sectional area of nearly all ice crystals below 20,000 µm2, effectively curtailing water loss. Simultaneously, the combination of vacuum packaging with the complex ice glaze effectively mitigated the degradation of IMP and free amino acids, maintaining low levels of K value (12.85 %) and TVB-N (11.28 mg N/100 g) throughout the 300-day frozen storage, retaining first-class freshness. Among the various treatment modalities assessed, the combined application of vacuum packaging and 0.3 % DSE-infused ice glazing emerged as the most effective in terms of preservation outcomes. This efficacious combination shows promising potential for the frozen storage of aquatic products and is therefore recommended for practical implementation.

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AIMS: The objectives of this study were to evaluate the effect of combination treatment with cold plasma (CP), vacuum packaging (VP), and hot water (HW) on the inactivation of foodborne pathogens on buckwheat seeds, and determined the germination rates of seeds and the quality of sprouts following combination treatment. METHODS AND RESULTS: Buckwheat seeds inoculated with Salmonella Typhimurium and Listeria monocytogenes were treated with CP, HW, CP + HW, VP + HW, or CP + VP + HW. The germination rates of the HW-, CP + HW-, VP + HW-, and CP + VP + HW-treated seeds and the antioxidant activities and rutin contents of the CP + HW- and CP + VP + HW-treated sprouts were determined. HW, CP + HW, and CP + VP + HW were found to reduce the levels of the two pathogens to below the detection limit (1.0 log CFU g-1) at 70°C. However, HW and CP + HW significantly reduced the germination rate of buckwheat seeds. CP + VP + HW did not affect the germination rate of seeds nor the antioxidant activities and rutin content of buckwheat sprouts. CONCLUSIONS: These results indicate that CP + VP + HW can be used as a novel control method to reduce foodborne pathogens in seeds without causing quality deterioration.

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The objective of this study was to determine the influence of hempseed meal (HSM) on goat meat characteristics. Goats (N = 10/treatment) were allocated to a diet concentration (0, 10, 20, or 30%) of HSM, fed for 60 days, and harvested. Carcass measurements were collected after chilling, and subsequently fabricated into wholesale subprimals. From the subprimals of the shoulder and leg, steaks were cut 2.54 cm thick, vacuum packaged, and assigned to laboratory methods: cook yield, instrumental color, lipid oxidation, microbial spoilage, and instrumental tenderness. HSM did not alter (p > 0.05) carcass characteristics, microbial spoilage, cook loss, or the thiobarbituric acid reactive substance (TBARS). However, a decrease in objective tenderness measurements (p < 0.05) was observed with greater concentrations of HSM supplementation in the diet. Instrumental surface color values for lightness (L*) indicated that steaks became lighter and less red (a*) as storage time increased (p < 0.05). Results suggest that HSM and storage time do not alter some goat meat traits, but HSM or storage time separately may influence goat meat quality. HSM may be an effective feed ingredient that does not alter carcass quality or meat yield.

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The quality changes of gutted rainbow trout in vacuum packaging (VP) and modified atmosphere packaging (MAP) with 40% CO2 + 60% N2 (MAP1), 60% CO2 + 40% N2 (MAP2), and 90% CO2 + 10% N2 (MAP3) were evaluated. The samples were stored at 3 ± 0.5 °C, and on days 1, 4, 7, 10, 13, and 16 of storage, microbiological, chemical, and sensory testing was performed. The aerobic plate count (APC) and psychrotrophic bacteria count (PBC) in VP fish exceeded the conventional limit of 7 log cfu/g on day 10, and in MAP1 and MAP2 fish on day 16, whereas in MAP3 fish, their number remained below that limit during the experiment. MAP significantly slowed down the growth of Enterobacteriaceae in trout, and the degree of inhibition increased with increasing CO2 concentration in the gas mixture. The lowest lactic acid bacteria numbers were detected in VP fish, whereas the highest numbers were determined in trout packaged in MAP2 and MAP3. Significantly lower numbers of hydrogen sulfide-producing (H2S) bacteria were detected in fish packed in MAP. Distinct patterns were observed for pH among treatments. The lowest increase in TBARS values was detected in VP and MAP3 fish, whereas in MAP1 and MAP2 fish, the TBARS values were higher than 1 mg MDA/kg on day 16 of storage when a rancid odor was detected. MAP inhibited the increase in total volatile basic nitrogen (TVB-N) content of trout compared to trout packaged in a vacuum. The sensory attributes of trout perceived by the sensory panel changed significantly in all experimental groups during storage. Based primarily on sensory, but also microbial, and chemical parameters, MAP has great potential for preserving fish quality and extending the shelf life of gutted rainbow trout from 7 days in VP to 13 days in MAP1 and MAP2, and to 16 days in MAP3.

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Extended storage duration often results in negative quality attributes of fresh or frozen beef steaks. This study focused on evaluating the fresh and cooked meat quality of beef steaks stored using vacuum packaging for 63 days. Steaks 2.54 cm thick were packaged into one of three thermoforming films VPA (250 µ nylon/EVOH/enhanced polyethylene coextrusion), VPB (250 µ nylon/EVOH/enhanced polyethylene coextrusion), or VPC (125 µ nylon/EVOH/enhanced/polyethylene coextrusion). Steaks placed in VPA were lighter (L*) and redder (a*) in surface color (p < 0.05) as the display period increased, whereas steaks packaged in VPB and VPC became darker. Yellowness, hue angle (Hue°), and chroma (C*) values were greater (p < 0.05) in steaks using VPC film as the storage period increased. Calculated spectral values of red to brown were greater (p < 0.05) for steaks in VPA and VPB than in VPC. However, steaks placed in VPC films contained greater (p < 0.05) forms of metmyoglobin and oxymyoglobin and lower calculated relative values of deoxymyoglobin. In addition, packaging treatment altered (p > 0.05) lipid oxidation, but storage time had a greater (p < 0.05) influence on purge loss, cook loss, and Warner-Bratzler shear force (WBSF). Current results suggest that the use of vacuum packaging for extended storage of beef steaks (>60) days is plausible.

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The objective of the current study was to optimize the cook-chill conditions of high-value whiteleg shrimp (Litopenaeus vannamei) processed using the sous vide (SV) technique and to assess the effects of various time-temperature combinations on the physicochemical, textural, and sensory qualities. For optimization, a Response Surface Methodology (RSM) approach utilizing a Central Composite Design (CCD) was adopted. Optimum SV cooking conditions to acquire minimum texture (hardness) of 7235 g was 13.48 min and 81.87 °C, expressible moisture of 18.48% was 14.5 min and 84.5 °C, and cook loss of 5.58% was 5 min and 75 °C. Texture (hardness) and expressible moisture decreased while cooking loss increased with increasing time-temperature treatment. Redness and yellowness values increased (p < 0.05) with increasing SV cooking time-temperature, but lightness values were nearly consistent in all treatments. With increasing time and temperature, TBARs and total carotenoid content increased (p < 0.05). However, the TBARs values were within accepted limits and ranged from 0.05 to 0.08 mg malonaldehyde/kg. Sensory evaluation indicated that all SV cooked samples were well accepted, with overall scores ≥7. These results suggest that the SV cooking temperature and time had a substantial impact on the textural, physicochemical, and sensory characteristics of shrimp. In addition, increasing time-temperature increased cooking and moisture loss, but decreased hardness and higher sensory scores made the product more acceptable to consumers.

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Effect of packaging at different vacuum levels such as 7.2 Pa (99.99% vacuum), 30 kPa (70.39%), 70 kPa (30.91%), and 101.33 kPa (0%, atmospheric condition) using a specially designed airtight container on physicochemical and microbial properties of beef brisket cuts during cold storage was investigated. Dramatic pH increase was found only in air atmospheric packaging. Higher vacuum level yielded higher water holding capacity and lower volatile basic nitrogen (VBN), 2-thiobarbituric acid (TBA), and growth rate of aerobic bacteria and coliforms, whereas the fatty acid composition showed no difference among various vacuum levels. The highest vacuum level (7.2 Pa) yielded no increases in VBN, TBA, and coliform and the least increase in aerobe counts. For bacterial communities, higher vacuum levels yielded higher proportions of Leuconostoc, Carnobacterium, and lactobacilli belonging to the phylum Firmicutes and lower proportions of Pseudomonas belonging to the phylum Proteobacteria. Predictive curves for bacterial communities showed that just a little oxygen significantly affects the bacterial dominance based on different oxygen dependence of individual bacteria and their logarithmic changes by vacuum level.

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This study was conducted to compare the effects of ultraviolet light (UV), chemical sanitizers, and heat treatments on Salmonella inactivation and preservation of almond quality. Whole, skinless, and sliced almonds, representing different shape and surface topography, were inoculated with a Salmonella cocktail consisting of S. Montevideo, S. Newport, S. Typhimurium, S. Heidelberg, and S. Enteritidis. Inoculated almonds (50 g) were treated by UV (30 mW/cm2, 30 or 60 min), 75 °C heat (up to 150 min), and chemical sanitizers (3 % hydrogen peroxide (H2O2) and 1 % cetylpyridinium chloride (CPC), 30 or 60 min) alone or in combinations. Uninoculated almonds were similarly treated for analyzing color, visual appearance, and weight changes. In general, UV treatment alone was ineffective in inactivating Salmonella; the 30- and 60-min UV treatments reduced Salmonella by 1.3 (± 0.1) and 1.7 (± 0.1), 2.7 (± 0.2) and 3.3 (± 0.1), and 1.3 (± 0.1) and 1.7 (± 0.1) log CFU/g on whole, skinless, and sliced almonds, respectively. Prior wetting of almonds with water and chemical solutions in a few cases significantly (P < 0.05) increased the UV inactivation of Salmonella. The most pronounced Salmonella killing effect achieved by the combined treatments were: 1-min H2O2 dipping followed by 60-min UV treatment for whole (3.0 logs) and skinless almonds (3.8 logs) and 1-min CPC dipping followed by 60-min UV treatment for sliced almonds (3.0 logs). However, none of those achieved >4 log reductions of Salmonella as required by FDA. The 30-min UV treatment produced discolored but overall acceptable almonds, whereas the 60-min UV treatment led to deteriorated almonds including a dark color, oil extraction, and shrunk kernel size. Prior wetting reduced the sample weight loss but caused local burning and kernel cracking. A sequential approach of a 60-min 75 °C heat treatment and two 30-min wet UV treatments successfully reduced Salmonella by >4 logs, but more severe kernel cracking occurred. In contrast, a single heat treatment of vacuum packaged whole almonds at 75 °C for 150 min was capable of achieving >5 log reductions of Salmonella while preserving almond color and visual qualities and minimizing weight loss. These results clearly demonstrated that the heat treatment was a much better processing technology than UV and sanitizers for raw almond pasteurization.

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