Extension of the Retail Display Life of Fresh Beef Packaged in Modified Atmosphere by Varying Lighting Conditions

The one-humped camel: The animal of future, potential alternative red meat, technological suitability and future perspectives

The 2020 world population data sheet indicates that world population is projected to increase from 7.8 billion in 2020 to 9.9 billion by 2050 (Increase of more than 25%). Due to the expected growth in human population, the demand for meats that could improve health status and provide therapeutic benefits is also projected to rise. The dromedary also known as the Arabian camel, or one-humped camel ( Camelus dromedarius), a pseudo ruminant adapted to arid climates, has physiological, biological and metabolic characteristics which give it a legendary reputation for surviving in the extreme conditions of desert environments considered restrictive for other ruminants. Camel meat is an ethnic food consumed across the arid regions of Middle East, North-East Africa, Australia and China. For these medicinal and nutritional benefits, camel meat can be a great option for sustainable meat worldwide supply. A considerable amount of literature has been published on technological aspects and quality properties of beef, lamb and pork but the information available on the technological aspects of the meat of the one humped camel is very limited. Camels are usually raised in less developed countries and their meat is as nutritionally good as any other traditional meat source. Its quality also depends on the breed, sex, age, breeding conditions and type of muscle consumed. A compilation of existing literature related to new technological advances in packaging, shelf-life and quality of camel meat has not been reviewed to the best of our knowledge. Therefore, this review attempts to explore the nutritional composition, health benefits of camel meat, as well as various technological and processing interventions to improve its quality and consumer acceptance. This review will be helpful for camel sector and highlight the potential for global marketability of camel meat and to generate value added products.

The Impact of the Fresh Pork Display Lamps on the Sensory Response of Consumers to Fresh Pork

Two studies were conducted to investigate the impact of fresh pork display lamps on consumers' sensory responses to pork products. In the first experiment, 63 participants were asked to evaluate pork products with different degrees of freshness under four fresh pork display lights and two LED lights. In the other experiment, 30 subjects participated in the Farnsworth-Munsell 100 hue test under the same lamps, with the aim of showing whether the fresh pork display lamps impaired color discrimination. The results showed that the light source had a significant effect on the color appearance evaluation of the pork products. The ratings for perceived freshness under the fresh pork display lamps were significantly higher than those of ordinary LED lamps, while the color discrimination performance of the subjects under those lamps was poor. It was demonstrated that improper component proportions of the light spectrum could influence observers' assessment of meat quality and weaken the observers' ability to distinguish the freshness level. Through this study, the authors would like to remind lamp users and manufacturers to not only be concerned about the improvement in the color appearance of pork, but also the need for consumers to be aware of the authentic freshness of the pork products.

The effect of essential oil of Anethum graveolens L. seed and gallic acid (free and nano forms) on microbial, chemical and sensory characteristics in minced meat during storage at 4 °C

The aim of this study was to evaluate the effect of gallic acid (GA) and essential oil (EO) of Anethum graveolens L. seed (forms of nanoliposome and free) on bacteriological, chemical and sensory properties of minced meat during storage. In this research, Escherichia coli (gram negative) and Staphylococcus aureus (gram positive) were used to examine the effect of these compounds on meat. The particle sizes (z-average diameter) of prepared nanoliposomes of EO and GA were in the range of 141 to 165 nm and 146-160 nm, respectively and the efficiency of encapsulation (EE %) in the current research was 51.76-69.8% in nano EO (NEO) and 53.23-67.07% in nano gallic acid (N-GA). Also, the outcomes indicated the treatment containing nano-liposomes had a better antimicrobial effect in both of bacteria. In present study, the Minimum Inhibitory Concentration (MIC) of GA, N-GA, EO and NEO for S. aureus was 0.62 ± 0.01, 0.62 ± 0.02, 0.62 ± 0.01 and 0.62 ± 0.01 mg/mL, respectively, and for E. coli was 0.62 ± 0.01, 0.62 ± 0.01, 1.25 ± 0.1 and 1.25 ± 0.1 mg/mL, respectively. Also, the results showed MBC (The Minimum Bactericidal Concentration) of GA, N-GA, EO and NEO for S. aureus was 0.62 ± 0.02, 0.62 ± 0.03, 1.25 ± 0.1 and 1.25 ± 0.1 mg/mL, respectively, and for E. coli was0.62 ± 0.01, 1.25 ± 0.1, 2.5 ± 0.2, 2.5 ± 0.2 mg/mL, respectively. The highest and lowest of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging were detected, in the Butylated hydroxytoluene (BHT) 200 and EO1%, respectively. Furthermore, after 18 day, minimum pH and Total volatile basic nitrogen (TVB-N) value were related to the N-GA2% on S. aureus with pH = 6.5 and NEO group (27 mg N/100 g), respectively. Finally, the treatment of NEO showed a higher acceptance score of sensory evaluation after 18 days. According to the outcomes of current investigation, the use of nanocapsulated EO and GA are effective (as a coating for food storage) and can increase the shelf life of minced meat.

Use of Algerian Type Ras El-Hanout Spices Mixture with Marination to Increase the Sensorial Quality, Shelf Life, and Safety of Whole Rabbit Carcasses under Low-O2 Modified Atmosphere Packaging

This study aimed to evaluate the effect of combined treatments with Ras El-Hanout spices mixture and marinade solution containing extra virgin olive oil, onion, garlic, and concentrated lemon juice on sensorial quality, shelf life, and safety of whole rabbit carcasses under low-O2 modified atmosphere packaging (MAP). The values of pH, water holding capacity, shear force, thiobarbituric acid reactive substances, total volatile basic nitrogen, color (CIE L*a*b*), sensorial tests, and spoilage microorganisms were determined in rabbit meat at 0, 5, 10, 15, and 20 days during a retail display at 7 ± 1 °C. The results indicated that the marination process using the Ras El-Hanout blend of spices improved the water-holding capacity of meat maintaining optimum pH values. This combined treatment delayed the growth of major spoilage microorganisms, lipid oxidation, protein degradation, and undesirable color changes compared to unmarinated samples from the fifth to the twentieth day of retail exposure. The shelf life of rabbit carcasses under low-O2 MAP could be extended to 20 days of retail display, while rabbit carcasses under aerobic display presented a shorter shelf life of 5 to 10 days. Instrumental and sensorial tests showed that low-O2 MAP enhanced the tenderness of whole rabbit carcasses, with those marinated with Ras El-Hanout being the most positively perceived by the panelists. Marination also inhibited the pathogen Campylobacter jejuni, thus increasing the microbiological safety of the packaged product. The overall results indicated that low-O2 MAP combined with the Ras El-Hanout spice blend and marinade solution may represent a promising strategy for retail establishments to improve the quality, shelf life, and safety of rabbit carcasses.

Inhibitory mechanisms of polyphenols on heme protein-mediated lipid oxidation in muscle food: New insights and advances

Lipid oxidation is a major cause of quality deterioration that decreases the shelf-life of muscle-based foods (red meat, poultry, and fish), in which heme proteins, particularly hemoglobin and myoglobin, are the primary pro-oxidants. Due to increasing consumer concerns over synthetic chemicals, extensive research has been carried out on natural antioxidants, especially plant polyphenols. The conventional opinion suggests that polyphenols inhibit lipid oxidation of muscle foods primarily owing to their strong hydrogen-donating and transition metal-chelating activities. Recent developments in analytical techniques (e.g., protein crystallography, nuclear magnetic resonance spectroscopy, fluorescence anisotropy, and molecular docking simulation) allow deeper understanding of the molecular interaction of polyphenols with heme proteins, phospholipid membrane, reactive oxygen species, and reactive carbonyl species; hence, novel hypotheses regarding their antioxidant mechanisms have been formulated. In this review, we summarize five direct and three indirect pathways by which polyphenols inhibit heme protein-mediated lipid oxidation in muscle foods. We also discuss the relation between chemical structures and functions of polyphenols as antioxidants.

Blue Light for Inactivation of Meatborne Pathogens and Maintaining the Freshness of Beef

ABSTRACT

Beef is rich in various nutrients but easily spoils due to bacterial contamination; thus, a bactericidal method is needed to inactivate meatborne pathogens while maintaining the freshness of beef. The present study was conducted to investigate for the first time the bactericidal effect of blue light (BL) at 415 nm against four meatborne pathogens (methicillin-resistant Staphylococcus aureus, Escherichia coli, Salmonella Typhimurium, and Listeria monocytogenes) both in vitro and inoculated onto the surface of fresh beef. The populations of the four pathogens on the nonirradiated control beef did not change significantly (P > 0.05), whereas a dose-dependent inactivation effect was found for BL-treated beef both in vitro and in vivo. On the beef cuts, BL at 109.44 J/cm2 inactivated 90% of inoculated cells of the tested strains (P < 0.05), and this inactivation effect was sustained during 7 days of cold storage. Insignificant changes in lipid oxidation rate, water holding capacity, and cooking loss were found during storage between the control beef and the beef irradiated at 109.44 J/cm2 at the same time. BL had a minor and nonsignificant effect on surface color and free amino acid concentrations. The pH of the treated beef increased more slowly (P < 0.05) than did that of untreated beef. These results suggest that BL could be a novel bactericide and could help maintain the freshness of beef.

HIGHLIGHTS

Light-emitting diodes (below 700 nm): Improving the preservation of fresh foods during postharvest handling, storage, and transportation

In order to maintain the original taste, flavors, and appearance, fresh foods usually do not go through complex processing prior to sale; this makes them prone to deterioration due to external factors. Light-emitting diodes (LEDs) have many unique advantages over traditional preservation technologies leading to their increasing application in the food industry. This paper reviews the luminescence principles of LED, the advantages of LED compared with traditional lighting equipment, and its possible preservation mechanism, and then critically summarizes the beneficial effects of LED irradiation on the ripening and aging process of various fruits and vegetables (climacteric and non-climacteric). The activity changes of many enzymes closely related to crop development and quality maintenance, and the variation of flavor components caused by LED irradiation are discussed. LED illumination with a specific spectrum also has the important effect of maintaining the original color and flavor of meat, seafood, and dairy products. For microorganisms attached to the surface of animal-derived food, both 400-460 nm LED irradiation based on photodynamic inactivation principle and UV-LED irradiation based on ultraviolet sterilization principle have high bactericidal efficacy. Although there is still a lack of useful standards for matching optimal LED irradiation dose with wavelength, perhaps in the near future, the improved LED irradiation system will be applied extensively in the food industry.

Correlation of Bioelectrical Impedance With Freshness Quality Attributes of Beef Longissimus Lumborum Steaks

The quality attributes of beef longissimus lumborum during 15 d of retail display were assessed using surface bioelectrical impedance analysis (S-BIA) and internal bioelectrical impedance analysis (I-BIA). Beef loins (N = 18) were obtained from 3 commercial processors with 3 postmortem (PM) ages (27, 34, and 37 d). Loins were fabricated into twelve 2.54-cm-thick steaks, subdivided into 6 consecutively cut pairs, and randomly assigned to one of 6 display days (DD): 0, 3, 6, 9, 12, or 15. Steaks were assessed for S-BIA and I-BIA. Three locations were analyzed within each steak: top, middle, and bottom. Microbiological analysis, BIA, pH, instrumental color, proximate composition, and lipid oxidation were measured. There was a location × PM day × DD interaction (P &lt; 0.05) for longissimus lumborum steaks for S-BIA. Among all 3 locations, steaks aged 27 d had higher (P &lt; 0.05) S-BIA values on day 9 and 12 than steaks aged 34 and 37 d. There were no location × PM day × DD or two-way interactions (P &gt; 0.05) for I-BIA. Display day affected (P &lt; 0.05) all instrumental color data regardless of PM aging times. Among all PM aging times, steaks aged 27 d were 13% and 7% higher for a* and b* , respectively, compared with 34 and 37 d PM. There was a PM day × DD interaction (P &lt; 0.05) for aerobic plate counts (APC). From day 0 and 9 of display, APC of steaks aged 27 d PM were 1 to 2.0 log colony-forming units/cm 2 lower than steaks aged 34 and 37 d. Quality attributes, including a*, b* , APC, and thiobarbituric acid reactive substances, were correlated (r = 0.70, − 0.64, − 0.56, and 0.69, respectively) with S-BIA. Overall, BIA values increased on aerobically packaged longissimus lumborum steaks and were correlated with various freshness quality parameters.

Effects of nano-chitosan coatings incorporating with free /nano-encapsulated cumin (Cuminum cyminum L.) essential oil on quality characteristics of sardine fillet

Nowadays, adding biological compounds to food packaging is one of the types of active packaging. The aim of this study was to prepare a new degradable coating with free and nano-encapsulated Cumino cyminum L. essential oil (CCEO) with nanochitosan (Nch) base to evaluate the microbial, chemical and sensory properties of sardine fillet samples for 16 days at 4 °C. Nanoliposome using different soy lecithin ratios and cholesterol concentrations (60:0, 50:10, 40:20, and 30:30) and technique of thin-film hydration-sonication, were prepared with a range of 140-164 nm size. Encapsulation efficiency (EE) and distribution of nanoliposomes size were calculated 0.80-0.90 and 49.85-73.01% respectively. To coat sardine fillet samples, nanoliposomes with the lower size of droplet and higher EE percent were selected. The outcomes indicated that coating treatments can effectively inhibit microbial growth and chemical spoilage reflected at lower pH, peroxide value (PV) and thiobarbituric acid reactive substances (TBARs) (P < 0.05). In fact, the results of chemical and microbiological characteristics showed that the samples treated with nanocitosan/nano essential oil (NEO) showed the lowest value among other treatments during the experimental period, in the following, Nch-EO, Nch and control. pH, PV, TBARs, total viable counts (TVC), total pseudomonads count (TPC), and lactic acid bacteria (LAB) were 6.85, 0.03 (mg MDA/kg), 5.23 (mEq/kg), 3.67 (CFU/g), 3.47 (CFU/g), and 4.7 (CFU/g), respectively for Nch-NEO at the end of storage time. In addition, during the experimental period, the highest sensory properties were obtained for the Nch-NEO group. Encapsulation of CCEO reduces the rate of diffusion, thus increasing antimicrobial and antioxidant activity, as well as improving sensory properties. According to the results of this study, CCEO-encapsulated nanochitosan coatings can be used as a potent coating to increase sardine shelf life.

Improvement of the Shelf-Life Status of Modified Atmosphere Packaged Camel Meat Using Nisin and Olea europaea Subsp. laperrinei Leaf Extract

The impact of combined biopreservation treatment with Olea europaea subsp. laperrinei leave extracts (laper.OLE) and nisin on the quality attributes of camel steaks packaged under high O₂ (80%) and CO₂ (20%) atmosphere was investigated during refrigerated (1 ± 1 °C) long-term storage. As measured by reversed phase HPLC/DAD analysis, oleuropein is the phenolic compound most present in the chemical composition of laper.OLE (63.03%). Camel steaks treated with laper.OLE had a lower concentration of thiobarbituric acid-reactive substances (TBA-RSs) in the course of 30 days of storage. Surface metmyoglobin (MetMb) increased at a reduced rate in laper.OLE-treated samples compared to control samples. Neither modified atmosphere packaging (MAP) nor biopreservation treatments significantly altered the tenderness of camel steaks, expressed in terms of Warner-Bratzler shear force (WBSF), as compared to control samples. After 30 days of storage, psychrotrophic bacteria and Pseudomonas spp. counts were significantly lower in camel steaks treated with a combination of laper.OLE and nisin than in untreated steaks. Moreover, samples treated with laper.OLE received higher scores on bitterness acceptability. In sum, the use of combined biopreservation methods could be a sustainable solution for the preservation and promotion of the quality characteristics of camel meat in arid regions.

Assessment of Dairy Product Safety Supervision in Sales Link: A Fuzzy-ANP Comprehensive Evaluation Method

An evaluation index system is developed to assess food safety supervision in the sales links of dairy products. Evaluation research is conducted using the fuzzy-ANP comprehensive evaluation model to assess the product safety supervision of dairy products in the sales link based on 307,705 survey data acquired from 1,501 online and offline dairy businesses in China. Evaluation results show that (1) the overall situation of dairy product safety supervision in the sales link is encumbered by the fact that the online situation of dairy product safety supervision in the sales link is general. It does not achieve a relatively good level; (2) the investment in food safety supervision of dairy products in the sales link is insufficient for the online e-commerce platforms. Especially, the processes of reviewing and approving relevant business sales qualification must be improved; (3) online business types do not directly determine the situation of dairy product safety supervision in the sales link, but the operating environment, sales staff quality, and warehousing management are common regulatory weaknesses; and (4) for offline provinces, the level of economic development can affect the situation of dairy product safety supervision in the sales link. Aside from emphasizing sales qualifications, economically backward provinces should improve the supervision of the operating environment, sales equipment, sanitary status of workers, and other aspects.

UV-C inactivation of foodborne bacterial and viral pathogens and surrogates on fresh and frozen berries

Outbreaks of foodborne illness associated with berries often involve contamination with hepatitis A virus (HAV) and norovirus but also bacteria such as Escherichia coli O157:H7 and parasites such as Cyclospora caytanensis. We evaluated the applicability of UV-C to the inactivation of pathogens on strawberries, raspberries and blueberries. Our three-step approach consisted of assessing the chemical safety of UV-C-irradiated berries, evaluating the sensory quality after UV-C treatment and finally studying the inactivation of the target microorganisms. Treatments lasting up to 9 min (4000 mJ cm^-2) did not produce detectable levels of furan (<5 μg/kg), a known photolysis product of fructose with genotoxic activity and thus were assessed to be toxicologically safe. No effect on taste or appearance was observed, unless treatment was excessively long. 20 s of treatment (an average fluence of ~ 212 mJ cm^-2) reduced active HAV titer by >1 log₁₀ unit in 95% of cases except on frozen raspberries, while 120 s were required to inactivate murine norovirus to this extent on fresh blueberries. The mean inactivation of HAV and MNV was greater on blueberries (2-3 log₁₀) than on strawberries and raspberries (<2 log₁₀). MNV was more sensitive on fresh than on frozen berries, unlike HAV. Inactivation of Salmonella, E. coli O157:H7 and Listeria monocytogenes was poor on all three berries, no treatment reducing viable counts by >1 log₁₀ unit. In most matrices, prolonging the treatment did not improve the result to any significant degree. The effect was near its plateau after 20 s of treatment. These results provide insight into the effectiveness of UV-C irradiation for inactivating bacterial and viral pathogens and surrogates on fresh and frozen berries having different surface types, under different physical conditions and at different levels of contamination. Overall they show that UV-C as single processing step is unsuitable to inactivate significant numbers of foodborne pathogens on berries.

Carbon Monoxide in Meat and Fish Packaging: Advantages and Limits

Due to increased demands for greater expectation in relation to quality, convenience, safety and extended shelf-life, combined with growing demand from retailers for cost-effective extensions of fresh muscle foods’ shelf-life, the food packaging industry quickly developed to meet these expectations. During the last few decades, modified atmosphere packaging (MAP) of foods has been a promising area of research, but much remains to be known regarding the use of unconventional gases such carbon monoxide (CO). The use of CO for meat and seafood packaging is not allowed in most countries due to the potential toxic effect, and its use is controversial in some countries. The commercial application of CO in food packaging was not then considered feasible because of possible environmental hazards for workers. CO has previously been reported to mask muscle foods’ spoilage, and this was the primary concern raised for the prohibition, as this may mislead consumers. This review was undertaken to present the most comprehensive and current overview of the widely-available, scattered information about the use of CO in the preservation of muscle foods. The advantages of CO and its industrial limits are presented and discussed. The most recent literature on the consumer safety issues related to the use of CO and consumer acceptance of CO especially in meat packaging systems were also discussed. Recommendations and future prospects were addressed for food industries, consumers and regulators on what would be a “best practice” in the use of CO in food packaging. All this promotes high ethical standards in commercial communications by means of effective regulation, for the benefit of consumers and businesses in the world, and this implies that industrialized countries and members of their regulatory agencies must develop a coherent and robust systems of regulation and control that can respond effectively to new challenges.

Effect of several packaging conditions on the microbiological, physicochemical and sensory properties of ostrich steaks during refrigerated storage

A total of 365 ostrich steaks were packaged in air (AIR), vacuum (VAC), MAP1 (70% O₂ + 30% CO₂), MAP2 (30% O₂ + 30% N₂ + 40% CO₂), MAP3 (20% O₂ + 30% N₂ + 50% CO₂), MAP4 (50% N₂ + 50% CO₂), MAP5 (20% N₂ + 80% CO₂) or MAP6 (100% CO₂). Microbial counts (10 groups), pH, Aw and sensory properties (nine-point hedonic scale) were determined on days 0, 1, 3, 7 and 15 of storage (4 °C). On day 0, microbial counts (log₁₀ cfu/g) ranged from undetectable levels (Brochothrix thermosphacta, enterococci) to 3.21 ± 0.63 (total aerobic counts -TAC-). The highest and the lowest microbial loads throughout storage were observed in AIR and MAP6, respectively. On day 15 TAC as high as 9.96 ± 0.20 log₁₀ cfu/g were found in AIR. The shelf-life (time until overall acceptability score fell below 5) was 3 days (MAP1, MAP2), 7 days (MAP3, AIR) or 15 days (MAP4, MAP5, MAP6). Only for VAC the shelf-life limit extended beyond 15 days.

Continuous Hydrothermal Synthesis of Inorganic Nanoparticles: Applications and Future Directions

Nanomaterials are at the leading edge of the emerging field of nanotechnology. Their unique and tunable size-dependent properties (in the range 1-100 nm) make these materials indispensable in many modern technological applications. In this Review, we summarize the state-of-art in the manufacture and applications of inorganic nanoparticles made using continuous hydrothermal flow synthesis (CHFS) processes. First, we introduce ideal requirements of any flow process for nanoceramics production, outline different approaches to CHFS, and introduce the pertinent properties of supercritical water and issues around mixing in flow, to generate nanoparticles. This Review then gives comprehensive coverage of the current application space for CHFS-made nanomaterials including optical, healthcare, electronics (including sensors, information, and communication technologies), catalysis, devices (including energy harvesting/conversion/fuels), and energy storage applications. Thereafter, topics of precursor chemistry and products, as well as materials or structures, are discussed (surface-functionalized hybrids, nanocomposites, nanograined coatings and monoliths, and metal-organic frameworks). Later, this Review focuses on some of the key apparatus innovations in the field, such as in situ flow/rapid heating systems (to investigate kinetics and mechanisms), approaches to high throughput flow syntheses (for nanomaterials discovery), as well as recent developments in scale-up of hydrothermal flow processes. Finally, this Review covers environmental considerations, future directions and capabilities, along with the conclusions and outlook.

Influence of vacuum-ageing duration of whole beef on retail shelf life of steaks packaged with oregano (Origanum vulgare L.) active film under high O2

Beef Longissimus lumborum (LL) was no aged (LL0), aged for 7 days (LL7) and 14 days (LL14) under vacuum at 1 ± 1 °C. The obtained beefsteaks were packaged in high oxygen (Hi-O2) with active packaging (AP) during 13-21 days at 1 ± 1 °C. Redness (CIE a* values), metmyoglobin percentage (MetMb%), total flora (PCA), thiobarbituric acid-reactive substances (TBA-RS), instrumental tenderness (Warner-Bratzler shear force: WBSF), and sensory analyses were performed. The various variables differed amongst the ageing times and packaging systems (AP vs. control). Three and ten additional days of retail shelf life were observed for steaks from LL7 and LL14, respectively. AP increased efficiently the retail shelf life of beefsteaks, but did not affect meat tenderness. The extended ageing from 7 to 14 days also induced higher tenderness in beefsteaks and did not show any affect negative effect on other quality parameters. Innovative technology referring to ageing under vacuum combined with Hi-O2 MA/AP would be desirable for beefsteaks during display and constituted a good alternative for meat supermarkets.

RAPID COMMUNICATION: Impact of contemporary light sources on oxidation of fresh ground beef

Meat color is considered one of the driving factors in consumer purchasing decisions. The objective of this study was to determine the impact of 2 different lighting sources on color and lipid oxidation of ground beef patties in a controlled environment. USDA Select top rounds ( = 20) were processed to produce ground beef at 2 different fat levels (5 and 25%) and made into patties (113.4 g). Patties were packaged with oxygen permeable polyvinyl chloride, assigned to one of three lighting treatments (low UV fluorescent [FLO], light emitting diode [LED], and no light [DRK, negative control]), and placed within deli cases at 5°C. Patty removal for evaluation occurred on retail display d 1, 3, 5, and 7. Objective color measurements were obtained using a HunterLab MiniScan 45/0 LAV. These values were utilized to determine myoglobin redox forms as a measure of myoglobin oxidation. Additionally, thiobarbituric acid reactive substances (TBARS) were measured to indicate lipid oxidation. Objective color measurement for a* (redness), decreased for all light treatments by retail display day ( < 0.0001). Oxymyoglobin values for all light treatments decreased daily but showed no differences between treatments until d 5 ( < 0.0001) where DRK > LED > FLO. Conversely, metmyoglobin values increased daily ( < 0.0001), but showed no differences between treatments until d 5 where FLO > LED > DRK. TBARS values increased by day for each fat percentage ( < 0.0001) with 5% fat patties having higher TBARS values indicating great oxidation occurring in the phospholipids than adipose tissues. Results indicate that light treatment affected discoloration and metmyoglobin formation in ground beef patties LED lighting may lead to increased meat quality shelf life in a retail setting.

Mechanical and moisture sensitivity of fully bio-based dialdehyde carboxymethyl cellulose cross-linked soy protein isolate films

Dialdehyde carboxymethyl cellulose (DCMC) crosslinked soy protein isolate (SPI) films were prepared by solvent casting method. Effect of DCMC treatment on mechanical properties, water sensitivity, light barrier properties and thermal stability were investigated. Significant increase in tensile strength (TS) was observed (up to 218%), suggesting occurrence of highly effective crosslinking between SPI and DCMC. Significant improvement in TS compared to other dialdehyde polysaccharide crosslinking agents such as dialdehyde starch is likely due to higher compatibility of DCMC with SPI, as was further confirmed by SEM images. Crosslinking also led to reduction in water vapor permeability and moisture content along with an increase of insoluble mass percentage, indicating improvement in water resistance of these bio-based protein films. Thermal stability of protein films also showed improvement post crosslinking of DCMC.

Effect of Lactic Acid Bacteria on Beef Steak Microbial Flora Stored Under Modified Atmosphere and on Listeria Monocytogenes in Broth Cultures

Beef steaks were inoculated with one or other of two protective strains of lactic acid bacteria, the bacteriocinogenic Lactobacillus sakei CTC 372 or the uncharacterised Lactobacillus CTC 711. They were stored under modified atmospheres (20–40% CO2). Inoculation of meat with both strains inhibited the growth of the spoilage bacteria. Neither CO2 in the pack atmosphere, inoculation with protective strains, nor a combination of both, affected formation of metmyoglobin or the development of off-odours. The formation of metmyoglobin in meat pigments and the sensory odour scores were compatible to those of fresh meat which had not undergone either oxidative deterioration or microbial spoilage. Listeria monocytogenes were inhibited in broth by meat surface microbiota containing either of the protective strains. With an initial population of 5.6 log cfu/mL, after 7 days incubation at 3°C, Listeria monocytogenes were recovered at log mean population of 2.8 log cfu/mL when neither protective strain was present. At 8°C, the population of Listeria monocytogenes recovered were reduced by about 2.5 or 1.5 log cfu/mL in the presence of Lactobacillus sakei CTC 372 or Lactobacillus CTC 711, respectively. At 25°C, the population of Listeria monocytogenes recovered from broth containing either protective strain were about 5 log cfu/mL less than the population recovered from broth containing Listeria monocytogenes only.

Advantages and Limitations on Processing Foods by UV Light

Fresh food products can be processed using UV light as a germicidal medium to reduce the food-borne microbial load. Water has been treated with UV light to obtain drinking water for quite some time. Pumpable fruit and vegetable products are generally very suitable for processing by UV light to reduce the microbial load. Today, most of these products are pasteurised to obtain microbiologically safe and nutritious products. However, pasteurisation can change the taste and flavour of such products because of the temperature and processing time. Juices from different sources can be treated by exposure to UV light at different doses. On the other hand, variables such as flow rate, exposure time, type of fruit product, juice colour and juice composition, among other variables, need to be studied to obtain fruit products with reduced microbial load, increased shelf life and adequate sensory and nutritional characteristics. Reduction of microbial load through UV light application as a disinfection medium for food products other than liquids is also being studied. Moreover, UV technology could be a source for pasteurisation of liquids, or disinfection of solid foods as an alternative technology, instead of thermal treatment or application of antimicrobial compounds.

Combined Effect of Modified Atmosphere Packaging and Addition of Lycopene Rich Tomato Pulp, Oregano and Ascorbic Acid and Their Mixtures on the Stability of Beef Patties

Beef patties were treated with ascorbic acid, oregano extract, lycopene rich tomato pulp (LRTP) and their mixtures, packaged in modified atmosphere and stored at 2°C. Lipid oxidation (TBARS formation), metmyoglobin formation, psychrotrophic bacterial counts and sensory odour and discolouration were analyzed throughout 20 days of storage. TBA values of beef patties containing oregano were the lowest ( p < 0.05); those containing ascorbic acid and LRTP alone were also significantly lower ( p < 0.05) than the control. The formation of surface metmyoglobin was significantly delayed ( p < 0.05) by the addition of oregano alone and its mixtures with ascorbic acid and/or LRTP. Psychrotrophic bacterial counts were significantly lower ( p < 0.05) in patties treated with 500 ppm oregano. Sensory colour and odour characteristics of beef patties were in agreement with the results of lipid and pigment oxidation. The antioxidant ability of oregano was dependent on the concentration; the presence of 500 ppm extended the shelf life of beef patties by about 8 days. LRTP alone exerted a limited antioxidant effect, while its combination with oregano resulted in a reduction of the antioxidative effect of the latter.

Rapid Discoloration of Aged Beef Muscles after Short-Term/Extreme Temperature Abuse during Retail Display

The objective of this study was to evaluate the effects of a short-term/extreme temperature abuse (STA) on color characteristics and oxidative stability of aged beef muscles during simulated retail display. Two beef muscles (longissimus lumborum, LL and semitendinosus, ST) were aged for 7 (A7), 14 (A14), 21 (A21), and 28 d (A28), and further displayed at 2℃ for 7 d. The STA was induced by placing steak samples at 20℃ for 1 h on the 4th d of display. Instrumental and visual color evaluations, ferric ion reducing capacity (FRC) and 2-thiobarbituric acid reactive substances (TBARS) assay were performed. Initially, redness, yellowness and hue angle of all beef muscles were similar, regardless of aging time before display (p>0.05). An increase in postmortem aging time increased lipid oxidation and caused a rapid discoloration after STA during display (p<0.05). ST muscle was more sharply discolored and oxidized after STA, when compared to LL muscle (p<0.05). The FRC value of beef muscles was decreased after 7 d of display (p<0.05). The results from the current study indicate adverse impacts of postmortem aging on color and oxidative stabilities of beef muscles, particularly under temperature abusing conditions during retail display. Thus, developing a specific post-harvest strategy to control quality attributes in retail levels for different muscle types and aging conditions would be required.

Size matters--The phototoxicity of TiO2 nanomaterials

Under solar radiation several titanium dioxide nanoparticles (nano-TiO2) are known to be phototoxic for daphnids. We investigated the influence of primary particle size (10, 25, and 220 nm) and ionic strength (IS) of the test medium on the acute phototoxicity of anatase TiO2 particles to Daphnia magna. The intermediate sized particles (25 nm) showed the highest phototoxicity followed by the 10 nm and 220 nm sized particles (median effective concentrations (EC50): 0.53, 1.28, 3.88 mg/L). Photoactivity was specified by differentiating free OH radicals (therephthalic acid method) and on the other hand surface adsorbed, as well as free OH, electron holes, and O2(-) (electron paramagnetic resonance spectroscopy, EPR). We show that the formation of free OH radicals increased with a decrease in primary particle size (terephthalic acid method), whereas the total measured ROS content was highest at an intermediate particle size of 25 nm, which consequently revealed the highest photoxicity. The photoactivities of the 10 and 220 nm particles as measured by EPR were comparable. We suggest that phototoxicity depends additionally on the particle-daphnia interaction area, which explains the higher photoxicity of the 10 nm particles compared to the 220 nm particles. Thus, phototoxicity is a function of the generation of different ROS and the particle-daphnia interaction area, both depending on particle size. Phototoxicity of the 10 nm and 25 nm sized nanoparticles decreased as IS of the test medium increased (EC50: 2.9 and 1.1 mg/L). In conformity with the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory we suggest that the precipitation of nano-TiO2 was more pronounced in high than in low IS medium, causing a lower phototoxicity. In summary, primary particle size and IS of the medium were identified as factors influencing phototoxicity of anatase nano-TiO2 to D. magna.

Chemical Profile, Antibacterial and Antioxidant Activity of Algerian Citrus Essential Oils and Their Application in Sardina pilchardus

Stored fish are frequently contaminated by foodborne pathogens. Lipid oxidation and microbial growth during storage are also important factors in the shelf-life of fresh fish. In order to ensure the safety of fish items, there is a need for control measures which are effective through natural inhibitory antimicrobials. It is also necessary to determine the efficacy of these products for fish protection against oxidative damage, to avoid deleterious changes and loss of commercial and nutritional value. Some synthetic chemicals used as preservatives have been reported to cause harmful effects to the environment and the consumers. The present investigation reports on the extraction by hydrodistillation and the chemical composition of three citrus peel essential oils (EOs): orange (Citrus sinensis L.), lemon (Citrus limonum L.) and bergamot (Citrus aurantium L.) from Algeria. Yields for EOs were between 0.50% and 0.70%. The chemical composition of these EOs was determined by gas chromatography coupled with mass spectrometry (GC/MS). The results showed that the studied oils are made up mainly of limonene (77.37%) for orange essential oil (EO); linalyl acetate (37.28%), linalool (23.36%), for bergamot EO; and finally limonene (51.39%), β-pinene (17.04%) and γ-terpinene (13.46%) for lemon EO. The in vitro antimicrobial activity of the EOs was evaluated against Staphylococcus aureus (S. aureus) using the agar diffusion technique. Results revealed that lemon EO had more antibacterial effects than that from other EOs. Minimal inhibitory concentrations (MICs) showed a range of 0.25–0.40 μL/mL. Lemon and bergamot citrus peel EOs were added at 1 × MIC and 4 × MIC values to Sardina pilchardus (S. pilchardus) experimentally inoculated with S. aureus at a level of 3.5 log₁₀ CFU/g and stored at 8 ± 1 °C. The results obtained revealed that the 4 × MIC value of bergamot reduced completely the growth of S. aureus from day 2 until the end of storage. The presence of EOs significantly extended lipid stability. Samples treated with bergamot EO displayed greater antioxidant activity than lemon EO. In fact, the oxidation rate is inversely proportional to the concentration of EO. At 1 × MIC and 4 × MIC values of bergamot EO, the levels of malonaldehyde compared to the control samples were 1.66 and 1.28 mg malonaldehyde/kg at the end of storage, corresponding to inhibition percentages of 42.76% and 55.87%, respectively. These results suggest the possibility that citrus EOs could be used as a way of combating the growth of common causes of food poisoning and used as potent natural preservatives to contribute to the reduction of lipid oxidation in sardines.

Use of UV-C postharvest treatment for extending fresh whole tomato (Solanum lycopersicum, cv. Zinac) shelf-life

The effect of UV-C treatments (0.32, 0.97, 2.56, 4.16 and 4.83 kJ.m(-2) at 254 nm) on the physical-chemical properties [colour, texture, total phenolic content (TPC), weight loss (WL)], and mesophylic counts of whole tomato, was evaluated during 15 days at 10 °C. During storage, the Ctr samples acquired faster red colour than all UV-C samples (higher a* and lower °h values). Comparing texture of Ctr and UV-C samples at 15(th) storage day, an increase of 9 and 8 % on firmness of treated samples at low UV-C intensities (0.32 and 0.97 kJ.m(-2), respectively) was observed. At the end of the storage, Ctr samples showed ca. 4 Log10 of mesophylic load, and the samples treated at 0.97 and 4.83 kJ.m(-2) revealed the lowest microbial load (1.9 and 3.2 Log10, respectively). These results indicate that UV-C radiation, at an appropriate dose, combined with low storage temperature (10 °C) are an effective method to preserve the postharvest life of tomato, without adversely affecting quality parameters.

Comparative studies of cytotoxic and apoptotic properties of different extracts and the essential oil of Lavandula angustifolia on malignant and normal cells

Lavender (Lavandula angustifolia Mill.) is a bush-like shrub from Lamiaceae. The herb has been used in alternative medicine for several centuries. In this study, the cytotoxicity and the mechanisms of cell death induced by 3 different extracts of aerial parts and the essential oil of L. angustifolia were compared in normal and cancerous human cells. Malignant (HeLa and MCF-7 cell lines) and nonmalignant (human fibroblasts) cells were incubated with different concentrations of the plant extracts. Cell viability was quantified by MTS assay. Apoptotic cells were determined using propidium iodide staining of DNA fragmentation by flow cytometry (sub-G1 peak). The molecules as apoptotic signal translation, including Bax and cleaved PARP, were identified by Western blot. Ethanol and n-hexane extracts and essential oil exhibited significant cytotoxicity to malignant cells but marginal cytotoxicity to human fibroblasts in vitro and induced a sub-G1 peak in flow cytometry histogram of treated cells compared to the control. Western blot analysis demonstrated that EtOH and n-hexane extracts upregulated Bax expression, also it induced cleavage of PARP in HeLa cells compared to the control. In conclusion, L. angustifolia has cytotoxic and apoptotic effects in HeLa and MCF-7 cell lines, and apoptosis is proposed as the possible mechanism of action.

Fatty acid profile, color and lipid oxidation of meat from young bulls fed ground soybean or rumen protected fat with or without monensin

The objective of the present study was to evaluate the meat quality and fatty acid (FA) profile of the muscle and subcutaneous fat of young bulls fed ground soybean grain (SB) or rumen protected fat (RPF) with (230 mg head(-1) day(-1)) or without monensin. Forty animals with an initial weight of 359 kg were allotted in a 2×2 factorial arrangement of treatments. The use of monensin increased the arachidonic and α-linolenic acids in the longissimus dorsi (LD) muscle and subcutaneous fat, respectively (P<0.05). The meat from the animals receiving RPF had greater C18:1 content (P<0.01). The CLA and C18:2 contents were greater in the LD muscle of the animals fed SB (P<0.01). However, α-C18:3 was greater in the LD muscle of animals fed RPF (P<0.01). In the subcutaneous fat, SB reduced C12:0 and C14:0 contents (P<0.01) and increased C18:0 (P<0.05). The inclusion of RPF increased the C18:1 and CLA contents (P<0.01) in the subcutaneous fat. Soybean elevated PUFA contents and increased susceptibility of muscle and subcutaneous fat to lipid oxidation.