Microbial changes under packaging conditions during transport and comparison between sampling methods of beef

Comparative Study of the Antibacterial Effects of S-Nitroso-N-acetylcysteine and Sodium Nitrite against Escherichia coli and Their Application in Beef Sausages

This study investigated the antibacterial effects of S-nitroso-N-acetylcysteine (SNAC) and sodium nitrite (NaNO2) against Escherichia coli and their application in beef sausages. Both SNAC and NaNO2 demonstrated pH-responsive antibacterial activity, with SNAC showing greater efficacy than NaNO2 (p < 0.05) at the same pH (3, 5, and 7). The reactive oxygen species (ROS) and reactive nitrogen species (RNS) induced in E. coli by SNAC were significantly higher than those induced by NaNO2 (p < 0.05), and both ROS and RNS values increased as the pH decreased. In addition, a lower pH led to more pores on the E. coli cell surface and increased membrane permeability, resulting in a more pronounced inhibitory effect. When applied to a beef sausage, SNAC-treated sausages had significantly lower total colony counts and carbonyl content compared to NaNO2-treated ones (p < 0.05). Consequently, SNAC shows great potential as a replacement for NaNO2 in meat products.

Preservative effect of pomegranate-based marination with β-resorcylic acid and cinnamaldehyde on the microbial quality of chicken liver

Chicken liver is considered a delicacy in the Middle East where pomegranate molass is commonly used as a salad dressing and in marinade recipes. Marinated chicken liver is a common entrée and represents a value-added product compared to the otherwise unmarinated liver which commands a lower price. The aim of this study was to investigate the inhibitory effects of a pomegranate-based marinade alone or following the addition of cinnamaldehyde or β-resorcylic acid on the spoilage microorganisms present in chicken liver during storage for 14 d at 4°C or under mild temperature abuse conditions (10°C). The pH and microbial populations of total plate count (TPC), lactic acid bacteria (LAB), Pseudomonas spp. (PS), yeast and mold (YM), and Enterobacteriaceae (EN) were tested during the storage period and the shelf life was determined (defined as 107 log cfu/g). Sensory analysis was also conducted. The pH increased by a greater extent in unmarinated samples as compared to marinated samples (with or without antimicrobials) upon storage. The initial TPC, LAB, PS, YM, and EN microbial populations in the chicken liver were 3.85 ± 0.79, 3.73 ± 0.85, 3.85 ± 0.79, 3.73 ± 0.87, and 3.69 ± 0.23 log cfu/g, respectively. The marinade decreased the microbial populations by 2 to 4 log cfu/g. The marinade and antimicrobial mixture decreased the microbial populations by 3 to 4 log cfu/g. Except for 1 sample, none of the marinated chicken liver samples with or without antimicrobials reached the end of shelf life even up to 14 d of storage at both 4°C and 10°C. The overall sensory score was rated around 6/9 for the treated samples.

Influence of Hempseed Meal on Fresh Goat Meat Characteristics Stored in Vacuum Packaging

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.

IoT-Enabled Electronic Nose System for Beef Quality Monitoring and Spoilage Detection

Food spoilage is a major concern in the food industry, especially for highly perishable foods such as beef. In this paper, we present a versatile Internet of Things (IoT)-enabled electronic nose system to monitor food quality by evaluating the concentrations of volatile organic compounds (VOCs). The IoT system consists mainly of an electronic nose, temperature/humidity sensors, and an ESP32-S3 microcontroller to send the sensors' data to the server. The electronic nose consists of a carbon dioxide gas sensor, an ammonia gas sensor, and an ethylene gas sensor. This paper's primary focus is to use the system for identifying beef spoilage. Hence, the system performance was examined on four beef samples stored at different temperatures: two at 4 °C and two at 21 °C. Microbial population quantifications of aerobic bacteria, Lactic Acid Bacteria (LAB), and Pseudomonas spp., in addition to pH measurements, were conducted to evaluate the beef quality during a period of 7 days to identify the VOCs concentrations that are associated with raw beef spoilage. The spoilage concentrations that were identified using the carbon dioxide, ammonia, and ethylene sensors were 552 ppm-4751 ppm, 6 ppm-8 ppm, and 18.4 ppm-21.1 ppm, respectively, as determined using a 500 mL gas sensing chamber. Statistical analysis was conducted to correlate the bacterial growth with the VOCs production, where it was found that aerobic bacteria and Pseudomonas spp. are responsible for most of the VOCs production in raw beef.

Probing the physicochemical characteristics of carrot sauce during storage

Globally, the prevalence of vit-A deficiency disorders i.e., xerophthalmia and nyctalopia is increasing especially in teenagers due to lifestyle shifts and undernutrition. This research was designed to develop carrot-supplemented tomato sauce to overcome vit-A deficiency and its related disorders. The carrot sauce was formulated with the addition of 50, 60, and 70% carrot pulp in tomato paste. The prepared sauce samples were tested for physical and biochemical changes in beta carotene (BC), lycopene, viscosity, pH, total soluble solids, titratable acidity, total plate count, and sensory parameters for 12 weeks. A non-significant effect of storage on BC, lycopene, and total soluble solids was observed. The total plate count, acidity, pH, and viscosity were influenced significantly. Sauce containing 60% of the carrot paste showed good sensory characteristics and 42.39 μg/g BC for the whole period of storage. It is concluded that carrot sauce can be used as tomato ketchup replacers to boost the overall quality of life by fighting against vit-A deficiency disorders.

Effects of lyophilized black carrot (Daucus carota L.) water extract on the shelf life, physico-chemical and microbiological quality of high-oxygen modified atmosphere packaged (HiOx-MAP) ground beef

In the present study, firstly, various properties of lyophilized water extracts (LBCWE) produced from fresh black carrot were determined. LBCWE was observed to be a rich source of monomeric anthocyanins (1188.40 ± 17.38 mg C3G/100 g; n = 4) and phenolics (2733.83 ± 17.78 mg GAE/100 g, n = 4). Secondly, ground beef containing LBCWE (Control, 100, 200 and 300 ppm) and packaged in HiOx-MAP (80% O₂ + 20% CO₂) was evaluated in terms of lipid oxidation, metmyoglobin (MetMb), color, pH and microbial counts during storage at 2.0 ± 0.5 °C for 12 days. By increasing level of LBCWE, the pH, lipid oxidation, MetMb and microbial counts were decreased (P < 0.01). The LBCWE significantly affected the color and microbial count parameters (P < 0.01). The highest redness and lowest microbial growth during storage was in the 300 ppm LBCWE group (P < 0.05). On the 12th day of storage, Pseudomonas and Enterobactericeae decreased 1.24 log and 1.46 log units in this group according to control. The shelf life of ground beef can be extended by 3 days with MAP + 300 ppm extract application.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13197-021-05044-1.