On-package dual sensors label based on pH indicators for real-time monitoring of beef freshness

Comparison of Two pH Responsive Color Changing Bio-Based Films Containing Wasted Fruit Pomace as a Source of Colorants

The main objective of this work is to develop and characterize novel bio-based sensor as intelligent food packaging film to monitor quality changes in fresh chicken meat. Chitosan (CS) and carboxymethyl cellulose (CMC) were used as polymer matrices for immobilization of pH sensitive color indicators. Generally considered as a food waste, blueberry (BP) and red grape skin pomace (RP) extracts were used as indicators at total phenolic content (TPC) of 0.06, 0.13, and 0.25 w/v for BP, and 0.006, 0.012, and 0.02 w/v for RP-based films. Color, mechanical, and intelligent material properties were determined. CS films were more elastic than CMC, while no significant changes in mechanical properties occurred after the addition of both extracts at all concentrations. Notable and eye recognizable color changes in dry films were seen. It was the most significant in the pH range from 4 to 7. For CMC-based films, color changed from violet to pink for BP extracts and from red to pink for RP extracts. For CS films, the changes were less significant. The color taint and intensity changed toward green in blueberry-based films and to orange in grape seed extract-based films. Significant color changes were observed after 46 hr in application tests on fresh chicken meat. This was correlated to pH changes of meat above 6 that was one of the parameters considered as an indication of spoilage. PRACTICAL APPLICATION: This work provides interesting data to food industry. It offers an idea and possibility of managing food waste from fruits and vegetables industry that makes problems and costs when needed to be disposed in a proper manner. Moreover, there is the possibility of producing novel kind of food packaging materials that could be used in order to check the end of food shelf-life in an inexpensive and natural way. Additional value lies in the fact that materials and procedures could be considered as sustainable.

A novel pH-sensing indicator based on bacterial cellulose nanofibers and black carrot anthocyanins for monitoring fish freshness

A novel intelligent pH-sensing indicator based on bacterial nanocellulose (BC) and black carrot anthocyanins (CA) was developed and characterized to monitor the freshness/spoilage of rainbow trout and common carp fillet during the storage at 4 °C. The indicator displayed wide color differences from red to gray over the 2-11 pH range, which was clearly discerned by the naked eye. The fabricated pH-sensing indicator showed distinguishable color changes during fresh (deep carmine color), best to eat (charm pink color), and spoiled (jelly bean blue and khaki colors) stages of both fish fillets. Moreover, a strong and positive correlation was obtained between the total color differences values of the indicator and bacterial count (R = 0.952 and 0.991) and total volatile basic nitrogen (R = 0.815 and 0.92) in rainbow trout and common carp samples. The results of this work demonstrated a significant correspondence of fish shelf life and color changes of a nanocellulose-based pH-sensing indicator.

Development of a freshness indicator for monitoring the quality of beef during storage

Quality of beef and detect changes in freshness during storage was evaluated using freshness indicator. The freshness indicator can indicate spoilage or freshness of the packaged product through color changes directly detected by the naked eye. We also monitored changes in pH, 2-thiobarbituric acid reactive substances, volatile basic nitrogen, and total bacterial count. A change in the color of the indicator reflects the pH of the headspace of the beef packaging. Beef was stored at 20 °C for 24 h, after which the color of the freshness indicator changed. Results of color change from freshness indicator are similar to quality parameters including chemical, microbiological, and sensory evaluation that are commonly used to characterize the freshness of beef. The results show that this freshness indicator is useful for determining the shelf life of beef products by monitoring physicochemical changes and microbial safety.

Capturing consumer value and clustering customer preferences in the Indonesian halal beef market

The Indonesian consumer behavior has changed over the last decades, and hence reviewing consumer value is crucial for the halal beef industry. This study explores halal beef consumer preferences and its segmentation. The research design constituted descriptive with a quantitative approach. Focus group discussions and consumer surveys were conducted through face-to-face interview toward 440 middle-class Muslim households in Indonesian top ten cities. The data analysis uses conjoint and clusters analysis. The essential attributes of halal beef in the order of priority are a red color, zero residues, latest production, halal guarantee label positions for each cluster, clean, tender, and flavor (p-value = 0.000). Beef consumers consist of four clusters comprising sanctity, clarity, quality, and safety. Based on demographic characteristics, the age and family size differences among groups were not significant, with each p-value at 0.356 and 0.189, while based on consumption and buying preference, each cluster has not significantly different in their beef consumption level, with a p-value at 0.102.

Intelligent pH-sensitive indicator based on starch-cellulose and alizarin dye to track freshness of rainbow trout fillet

A novel pH-sensitive indicator was prepared by incorporation of alizarin in a starch-cellulose paper to monitor the freshness of rainbow trout fillet. Water solubility of the fabricated indicator reduced by incorporation of alizarin, while the percentage of swelling didn't change. FTIR certified that alizarin was properly incorporated which was revealed by the formation of intermolecular hydrogen bonding in the cellulose-starch matrix. SEM and ultraviolet-visible spectrum results also demonstrated that alizarin had good compatibility with the components of the indicator. The alizarin-starch-cellulose indicator (ASC) had greater color efficiency from yellow to purple at pH 2-11 and greater color stability after two months of storage at 4 °C. It can be concluded that the color changes of ASC, from orange to reddish brown, were entirely corresponded with TVB-N contents of fish, which presents a satisfactory capability of developed indicator to identify the initiation of spoilage in the refrigerated fish fillet.

Application of invasive weed optimization and least square support vector machine for prediction of beef adulteration with spoiled beef based on visible near-infrared (Vis-NIR) hyperspectral imaging

Different multivariate data analysis methods were investigated and compared to optimize rapid and non-destructive quantitative detection of beef adulteration with spoiled beef based on visible near-infrared hyperspectral imaging. Four multivariate statistical analysis methods including partial least squares regression (PLSR), support vector machine (SVM), least squares support vector machine (LS-SVM) and extreme learning machine (ELM) were carried out in developing full wavelength models. Good prediction was obtained by applying LS-SVM in the spectral range of 496-1000 nm with coefficients of determination (R²) of 0.94 and 0.94 as well as root-mean-squared errors (RMSEs) of 5.39% and 6.29% for calibration and prediction, respectively. To reduce the high dimensionality of hyperspectral data and to establish simplified models, a novel method named invasive weed optimization (IWO) was developed to select key wavelengths and it was compared with competitive adaptive reweighted sampling (CARS) and genetic algorithm (GA). Among the four multivariate analysis models based on important wavelengths determined by IWO, the LS-SVM simplified model performed best where R² of 0.97 and 0.95 as well as RMSEs of 4.74% and 5.67% were attained for calibration and prediction, respectively. The optimum simplified model was applied to hyperspectral images in pixel-wise to visualize the distribution of spoiled beef adulterant in fresh minced beef. The current study demonstrated that it was feasible to use Vis-NIR hyperspectral imaging to detect homologous adulterant in beef.

Ethylene-vinyl Alcohol Copolymer-Montmorillonite Multilayer Barrier Film Coated with Mulberry Anthocyanin for Freshness Monitoring

Colorimetric films incorporated with anthocyanins as an indicator for freshness monitoring have aroused growing interest recently. However, the application of the films is limited by the easily oxidizable nature of anthocyanins. In this work, we developed a novel colorimetric film with a barrier by coating mulberry anthocyanin (MBA) on the internal side of an ethylene-vinyl alcohol copolymer-montmorillonite (EVOH-MMT) multilayer film. A facile layer-by-layer (LBL) assembly was employed under a parallel electric field to build the EVOH-MMT multilayer structure, in which the exfoliated MMT nanosheets were well-oriented and assembled on the EVOH matrix to form a tightly stacked layer between two EVOH layers. The interlayer of MMT significantly enhanced the barrier and mechanical properties of the films (below 40 layers). The interactions between EVOH and MMT and between EVOH and MBA were confirmed to be intermolecular hydrogen bonds. The colorimetric response of (EVOH-MMT)₄₀-MBA₃ to volatile ammonia and pH was sensitive, and the color change could be easily distinguished by the naked eye. The successful application of (EVOH-MMT)₄₀-MBA₃ to shrimp-freshness monitoring confirms its high potential for the freshness monitoring of packaged food.

Titanium Dioxide Nanotube-Based Oxygen Indicator for Modified Atmosphere Packaging: Efficiency and Accuracy

Colorimetric oxygen indicators can be applied for non-destructive testing in packaging; especially in modified atmosphere packaging (MAP). In this paper; titanium dioxide (TiO₂) nanotube; which is used as a semiconductor photocatalyst in oxygen indicators; was synthesized via a microwave-assisted hydrothermal method. X-Ray Diffraction (XRD) was used to analyze its crystal form and Scanning Electron Microscope (SEM).to characterize its morphology. Its properties were studied using Brunauer-Emmett-Teller (BET), Diffuse Reflection Spectrum (DRS), and Bluebottle experiments. The results showed that the synthesized TiO₂ nanotube was a mixture of rutile and anatase; with a specific surface area of 190.35 m²/g; and a wide band gap of 3.34 eV. Given the satisfactory performance; the TiO₂-based oxygen indicator was prepared and combined with glycerol; methylene blue; and hydroxyethyl cellulose (HEC). The oxygen indicator demonstrated excellent photocatalytic performance and effectively avoided excitation by visible light. We studied the rheological properties; thixotropic properties; and wettability of the indicator. The results demonstrated the printability of the indicator solution; which was then printed in the polyethylene terephthalate (PET) film by screen printing and applied to MAP. The application results showed that the prepared oxygen indicator was able to provide visual support to judge whether the packaging was intact and the food was safe.

Chemical and Biological Sensors for Food-Quality Monitoring and Smart Packaging

The growing interest in food quality and safety requires the development of sensitive and reliable methods of analysis as well as technology for freshness preservation and food quality. This review describes the status of chemical and biological sensors for food monitoring and smart packaging. Sensing designs and their analytical features for measuring freshness markers, allergens, pathogens, adulterants and toxicants are discussed with example of applications. Their potential implementation in smart packaging could facilitate food-status monitoring, reduce food waste, extend shelf-life, and improve overall food quality. However, most sensors are still in the development stage and need significant work before implementation in real-world applications. Issues like sensitivity, selectivity, robustness, and safety of the sensing materials due to potential contact or migration in food need to be established. The current development status of these technologies, along with a discussion of the challenges and opportunities for future research, are discussed.

Meat packaging solutions to current industry challenges: A review

Many advances have occurred in the field of smart meat packaging, and the potential for these to be used as tools that respond to challenges faced by industry is exciting. Here, we review packaging solutions to several immediate concerns, encompassing dark cutting, purge and yield losses, product traceability and provenance, packaging durability, microbial spoilage and safety, colour stability, environmental impacts, and the preservation of eating quality. Different active and intelligent packaging approaches to each of these were identified and are discussed in terms of their usefulness - to processors, retailers and/or consumers. From this, it became apparent that prior to selecting a packaging solution, industry should first define their criteria for success (e.g. How much purge is too much? What is a reasonable shelf-life to facilitate product turnover? Is the customer willing to pay for this?), and understand that packaging is not the sole solution, but acts as part of a holistic response to these issues.