In-Line Estimation of Fat Marbling in Whole Beef Striploins (Longissimus lumborum) by NIR Hyperspectral Imaging. A Closer Look at the Role of Myoglobin.

Fat marbling, the amount, and distribution of intramuscular fat, is an important quality trait for beef loin (Longissimus lumborum) and is closely connected to sensory properties such as tenderness, juiciness, and flavor. For meat producers, it would be of value to grade and sort whole loins according to marbling on the production line. The main goal of this study was to evaluate high-speed NIR hyperspectral imaging in interaction mode (760-1047 nm) for in-line measurement of sensory assessed marbling in both intact loins and loin slices. The NIR system was calibrated based on 28 whole striploins and 412 slices. Marbling scores were assessed for all slices on a scale from 1 to 9 by a trained sensory panel. The calibrated NIR system was tested for in-line measurements on 30 loins and 60 slices at a commercial meat producer. Satisfactory accuracy for prediction of marbling was obtained by partial least squares regression for both slices and whole loins (R2 = 0.81 & 0.82, RMSEP = 0.95 & 0.88, respectively). The concentration of myoglobin in the meat and its state of oxygenation has a strong impact on the NIR spectra and can give deviations in the estimated marbling scores. This must be carefully considered in industrial implementation.

Nutritional and Sensory Properties of Protein Hydrolysates Based on Salmon (Salmo salar), Mackerel (Scomber scombrus), and Herring (Clupea harengus) Heads and Backbones.

Protein hydrolysates based on salmon, mackerel, and herring heads and backbones were produced, and the sensory properties of the hydrolysates were evaluated by a highly trained sensory panel. The nutritional content of the products was evaluated, and the hydrolysates contained all the amino acids inherent to the raw material, including considerable levels of connective tissue amino acids glycine, proline, and hydroxyproline. Hydrolysates based on herring were the most flavor intense, whereas hydrolysates based on salmon were deemed more palatable. In this work, choice of fraction (heads vs. backbones) and enzyme had minor effects on sensory and nutritional properties, indicating that choice of raw material species was the major factor for flavor development in the produced protein hydrolysates. There were large variations in protein content and amino acid composition in the raw material fractions, but as expected, only minor variations were found in the final products.

Effect of Liquid Absorbent Pads and Packaging Parameters on Drip Loss and Quality of Chicken Breast Fillets.

Visible liquid inside food packages is perceived as unattractive to consumers, and may result in food waste-a significant factor that can compromise sustainability in food value chains. However, an absorber with overdimensioned capacity may cause alterations in texture and a dryer product, which in turn may affect consumers' satisfaction and repurchase. In this study we compared the effect of a number of liquid absorbent pads in combination with headspace gas composition (60% CO2/40% N2 and 75% O2/25% CO2) and gas-to-product volume ratio (g/p) on drip loss and quality of fresh chicken breast fillets. A significant increase in drip loss with an increasing number of liquid absorbent pads was documented. The increase was more pronounced in 60% CO2/40% N2 compared to 75% O2/25% CO2. By comparing packaging variants with a different number of liquid absorbent pads, a higher drip loss for all tested was found at g/p 1.8 compared to g/p 2.9. Total viable counts (TVC) were independent of whether there was free liquid in contact with the product, and TVC was independent of gas composition. Differentiation between the gas compositions was seen for specific bacterial analyses. While significant changes were observed using texture analysis, sensory evaluation of the chicken breast fillets did not show any negative effect in texture related attributes. This study demonstrates the importance of optimized control of meat drip loss, as product-adjusted liquid absorption may affect economy, food quality, and consumer satisfaction, as well as food waste.

Improved control of Listeria monocytogenes during storage of raw salmon by treatment with the fermentate Verdad N6 and nisin.

Fresh Atlantic salmon (Salmo salar) represents a healthy, nutritious food with global distribution and increasing consumption and economic value. Contaminating Listeria monocytogenes in fresh salmon represents a health hazard to consumers, is linked to extensive product recalls and is a major challenge for salmon processors. Verdad N6, a commercially available buffered vinegar, was evaluated as a treatment for raw salmon fillets either alone or in combination with the antimicrobial peptide nisin, with regard to anti-listerial effects under processing and storage, and influence on sensory quality and background microbiota. Salmon fillets were surface contaminated with L. monocytogenes and immersed in solutions of Verdad N6 or treated with nisin or a combination of these two treatments. Levels of L. monocytogenes were determined during vacuum-pack refrigerated storage. The use of Verdad N6 resulted in increased lag times and substantially reduced growth of L. monocytogenes. The inhibitory effects were dependent on Verdad N6 levels, immersion time, and storage time and temperature. A 5 s immersion in 10% Verdad N6 solution at 4 °C reduced growth of L. monocytogenes from log 2.8 to log 1 after 12 days of storage. Nisin (0.2-1 ppm) had listericidal effects up to 1 log but did not inhibit regrowth when used alone. Appropriate combinations of Verdad N6 and nisin led to L. monocytogenes levels no higher after 12 days of storage than the initial levels. The inhibitory effects were markedly lower at 7 °C than at 4 °C. Salmon with Verdad N6 showed reduced levels of total counts during storage indicating a longer shelf-life, and a shift in the dominating bacteria with reduced and increased relative levels of Enterobacteriaceae and lactic acid bacteria, respectively. Sensory analyses of raw and cooked Verdad N6 treated a non-treated salmon resulted in small differences. In summary, Verdad N6 is an option for production of high-quality raw salmon with increased shelf-life and enhanced food safety through its Listeria inhibiting effects. The application of Verdad N6 in combination with nisin treatment can further reduce the listeria-risks of these products.

Reduction and inhibition of Listeria monocytogenes in cold-smoked salmon by Verdad N6, a buffered vinegar fermentate, and UV-C treatments.

Contamination, survival and growth of Listeria monocytogenes in cold-smoked salmon represent serious health hazards to consumers and major challenges for salmon processors. Verdad N6, a commercially available buffered vinegar, was evaluated as an ingredient in cold-smoked salmon with regard to anti-listerial effects under processing and storage, sensory quality and consumer preference, effects on background microbiota and yield during production. Cold-smoked salmon with Verdad N6 added in the dry-salting process was produced. Salmon fillets were surface contaminated with a mix of L. monocytogenes. Levels of L. monocytogenes were determined during vacuum pack refrigerated storage for 29 days. The use of Verdad N6 resulted in increased lag times and reduced growth rates of L. monocytogenes. The inhibitory effects were dependent on Verdad N6 levels (0-2%), storage time and temperature (4 or 8 °C), type of contamination (between slices or on non-sliced salmon) and degree of smoking. The presence of dextrose (1%) in the recipe had no significant effects on L. monocytogenes levels after storage. On sliced salmon, complete growth inhibition at 4 °C storage could be obtained using 1% Verdad N6 compared to a 3 log increase in L. monocytogenes counts in control salmon. At abuse temperatures (8 °C), corresponding L. monocytogenes levels increased <2 log and 5-6 log during 29 days storage. On non-sliced salmon, 1% Verdad N6 provided complete growth reductions at 4 and 8 °C storage while L. monocytogenes in control salmon increased 2.3 and 4.6 log, respectively, in the same period. The use of Verdad N6 in combination with bactericidal UV-C treatments (fluence 50 mJ/cm2) provided an initial 0.8 log reduction and complete L. monocytogenes growth inhibition on subsequent storage at 4 and 8 °C. Salmon with Verdad N6 showed reduced levels of total counts during storage and a shift in the dominating bacteria with reduced and increased relative levels of Photobacterium and lactic acid bacteria, respectively. A consumer test showed no consistent differences in liking of salmon with and without Verdad N6. In summary, Verdad N6 is an option for the production of high quality cold-smoked salmon with enhanced food safety through its robust listeriostatic effects. The application of Verdad N6 in combination with listericidal UV-C light treatment can further reduce the listeria-risks of this ready-to-eat food product category.

Comparison of UV-C and Pulsed UV Light Treatments for Reduction of Salmonella, Listeria monocytogenes, and Enterohemorrhagic Escherichia coli on Eggs.

Ten percent of all strong-evidence foodborne outbreaks in the European Union are caused by Salmonella related to eggs and egg products. UV light may be used to decontaminate egg surfaces and reduce the risk of human salmonellosis infections. The efficiency of continuous UV-C (254 nm) and pulsed UV light for reducing the viability of Salmonella Enteritidis, Listeria monocytogenes, and enterohemorrhagic Escherichia coli on eggs was thoroughly compared. Bacterial cells were exposed to UV-C light at fluences from 0.05 to 3.0 J/cm2 (10 mW/cm2, for 5 to 300 s) and pulsed UV light at fluences from 1.25 to 18.0 J/cm2, resulting in reductions ranging from 1.6 to 3.8 log, depending on conditions used. Using UV-C light, it was possible to achieve higher reductions at lower fluences compared with pulsed UV light. When Salmonella was stacked on a small area or shielded in feces, the pulsed UV light seemed to have a higher penetration capacity and gave higher bacterial reductions. Microscopy imaging and attempts to contaminate the interior of the eggs with Salmonella through the eggshell demonstrated that the integrity of the eggshell was maintained after UV light treatments. Only minor sensory changes were reported by panelists when the highest UV doses were used. UV-C and pulsed UV light treatments appear to be useful decontamination technologies that can be implemented in continuous processing.

Projective mapping based on choice or preference: An affective approach to projective mapping.

This work explores a new affective approach to projective mapping, based on consumers' choices or preferences. Two sessions, one week apart, were performed with the same consumers, using whole bread as a case study. Overall liking ratings (OL) were gathered in blind conditions and samples were also profiled by a trained panel using generic descriptive analysis. Three projective mapping tests were performed in different scenarios. Consumers' categorization and product descriptions were explored when consumers based their positioning on the products' similarities and differences (analytical approach, "classic napping") both in blind and informed conditions, and when consumers were focusing on their preference or choice (affective approach). The affective approach to projective mapping successfully revealed consumers' drivers of liking and choice from a holistic perspective, where consumers summarized their main drivers for categorizing products as they would do when choosing in real life situations, based on their preferences.

A novel packaging method with a dissolving CO(2) headspace combined with organic acids prolongs the shelf life of fresh salmon.

The aim of this study was to evaluate a novel packaging method for fresh fish and to determine its effect on the bacterial growth in fresh salmon. Fresh salmon was packed with a small amount of 100% CO(2) (gas/product ratio 0.2/1.0 v/v) and a brine solution containing various combinations of citric acid (3% w/w, pH 5), acetic acid (1% w/w, pH 5) and cinnamaldehyde (200 microg/ml). Total bacterial counts, counts of sulphur reducing bacteria, lactic acid bacteria and Enterobacteriaceae as well as the bacterial composition in the product after storage were determined. The combination of CO(2) and organic acids completely inhibited bacterial growth during 14 days of storage at 4 degrees C both in inoculation experiments and in experiments on salmon with natural background flora. CO(2), acetic acid and citric acid alone each inhibited the growth of total bacterial counts, lactic acid bacteria, sulphur reducing bacteria and Enterobacteriaceae, but effects were enhanced in combinations. The addition of cinnamaldehyde did not influence bacterial growth. Analysis of the bacterial flora of salmon inoculated with different spoilage bacteria showed that Photobacterium phosphoreum and Carnobacterium maltaromaticum remained the dominating species after inoculation while Yersinia aldovae, Aeromonas salmonicida and Shewanella putrefaciens were outcompeted by other species. In addition, lactic acid bacteria from the natural background flora grew to high numbers. Combinations of CO(2) and acetic acid reduced the relative abundance of P. phosphoreum. All CO(2) dissolved in the product, thereby creating a product with the outer appearance of a vacuum package. Further work is needed to determine consumer acceptability of acid concentrations and to implement the packaging method for industrial purposes. However, implication of this packaging method in the industry may lead to a new packaging technology, combining the advantages of vacuum packaging (low space requirement) and modified atmosphere packaging (antimicrobial effect of CO(2)).