A pH-sensitive dye-based freshness indicator has been developed to monitor the quality status of pork neck through distinct color transitions, addressing a crucial need for improved food safety and real-time monitoring within the food industry. This system aims to boost consumer confidence and improve shelf-life estimates by offering transparent and immediate quality indicators. Aerobically packaged pork neck samples underwent accelerated testing at 25 °C for 36 h, followed by refrigeration experiments at typical distribution temperatures of 4 and 8 °C over 10 days. Measured pork neck quality parameters included total bacterial count (TBC), total volatile basic nitrogen (TVB-N), and pH levels. Visual observation and colorimetric analysis were used to assess the chromatic variations of the freshness indicator, which showed a significant shift from orange to green in response to the presence of TVB-N in the headspace of the pork packaging. The chromatic parameters of the freshness indicator exhibited a significant correlation with the pork quality values throughout the storage periods. The results highlight the ability of the freshness indicator to effectively convey quality information about pork through noticeable colorimetric changes.

The purpose of this study was to evaluate and validate methylene blue migration from printed time–temperature indicators (TTIs) into food. It also highlights the importance of establishing regulatory measures and safety standards for food packaging, suggesting that this can contribute to improving food packaging safety. Liquid chromatography–mass spectrometry (LC-MS/MS) was used to quantify methylene blue migration in various food simulant and food matrix samples. The results show that the level of methylene blue migration varies significantly depending on the chemical properties of the food mimetic and the composition of the food matrix. The established method demonstrated a high sensitivity, with limits of detection (LODs) of 0.0019–0.0706 μg/L (kg) and limits of quantification (LOQs) of 0.0057–0.2138 μg/L (kg). This study highlights the need for a regulatory framework to mitigate the health risks associated with methylene blue in intelligent packaging systems and argues that regulatory thresholds should be set to ensure food safety and quality.

Monitoring the freshness of perishable foods remains a challenge due to the lack of simple and reliable indicators that can visually reflect chemical and microbial changes. In this study, a colorimetric freshness indicator was developed using bromocresol green (BCG) and bromocresol purple (BCP), two pH-sensitive dyes with complementary transition ranges, to provide a visible and quantitative response corresponding to beef quality during cold storage. Cellulose acetate (CA) films were prepared by incorporating the dyes with different plasticizers—glycerol and polyethylene glycol (PEG 200 and PEG 400)—at varying ratios, resulting in 24 formulations. Based on color stability and sensitivity to trimethylamine (TMA) vapor, two optimized indicators were selected for further packaging tests with beef samples stored at 4 °C. Beef freshness was evaluated by total bacterial count (TBC), total volatile basic nitrogen (TVB-N), and pH, while volatile amines in the headspace were quantified using solid-phase microextraction–gas chromatography–flame ionization detection (SPME–GC–FID). The color difference (ΔE) of the indicators showed strong correlations with TBC and TVB-N, and a threshold of ΔE ≈ 12 provided a practical visual cue corresponding to the microbiological safety limit. The two indicators exhibited complementary functions, with G100-1 acting as an early-warning sensor and G100-2 maintaining contrast at later stages. These findings demonstrate the potential of this dual-indicator system as a simple, non-destructive tool for intelligent packaging applications.

Proteins are some of the most commonly used biomaterials in food technology, especially in food packaging, coatings, and additives. They are outstanding candidates for producing innovative food components due to their immense nutritional properties, molecular characteristics, biocompatibility, biodegradability, and safe status. Numerous application examples of protein-based films and coatings in food packaging also approve their significant role in food packaging materials. Sericin is a natural silk globular protein, which is usually discarded as a biological waste material after removing the fibroin for making silk products from the silk cocoon. In the current investigation, an attempt was made to extract this usually wasted silk protein from the silk cocoon, purify it, and study its potential applications in the food sector as a food packaging material. The sericin was extracted from the silk cocoon by the degumming method. The protein concentration of the extracted crude sericin sample was estimated by the standard Lowry’s method using the bovine serum albumin as the reference standard. Linearity was obtained (R² > 0.99), and the protein concentration of the crude sericin was found out to be 3.60 % (w/v). The purification of the crude protein was carried out by dialysis using a cellulose tubing with a molecular weight cutoff of 12 kDa, followed by freeze-drying. The protein concentration of the purified sericin was found out to be 3.47 % (w/v). Following extraction, sericin can be used as the food packaging material. Proteins, especially sericin, which is a byproduct, can provide a low-cost and naturally occurring raw material to be used as green formulation ingredients in the food industry as a food packaging material. Further research is under process to evaluate the antimicrobial and antioxidant potential of the extracted sericin and study its applications, including food packaging materials.

In this study, we developed and validated an analytical method to evaluate the heavy metal elution from an active packaging material’s oxygen absorber to a food simulant. Using water, 4% acetic acid, n-heptane, 20% ethanol, and 50% ethanol as food simulants, we quantified cobalt, copper, platinum, and iron with inductively coupled plasma-mass spectrometry. The method was thoroughly validated for linearity, accuracy, precision, LOD, and LOQ through inter-day and intra-day analysis repetitions. R² values ranged from 0.9986 to 1.0000, indicating excellent linearity. The LOD values ranged from 0.00002 to 0.2190 mg/kg, and the LOQ values ranged from 0.00007 to 0.6636 mg/kg. The method’s accuracy was 95.14% to 101.98%, with the precision ranging from 0.58% to 10.37%. Our results confirmed the method’s compliance with CODEX standards. Monitoring the oxygen absorber revealed undissolved platinum, cobalt levels from 0.10 to 19.29 μg/kg, copper levels from 0.30 to 976.14 μg/kg, and iron levels from 0.06 to 53.08 mg/kg. This study established a robust analytical approach for evaluating the heavy metal elution from oxygen absorbers, ensuring safety in the food industry.

The seafood industry is increasingly adopting intelligent packaging to preserve product quality and improve freshness transparency. This study developed and evaluated a pH-sensitive freshness indicator (FI) for skate sashimi (Zearaja chilensis). This product is consumed at varying stages of fermentation. The FI incorporated bromothymol blue (BTB) and bromocresol purple (BCP) in a polymer matrix. It targeted volatile basic nitrogen (VBN) compounds, with trimethylamine (TMA) as the primary marker. As freshness declined, VBN compounds accumulated in the package headspace and caused a gradual FI color change from yellow to blue through pH variation. ΔE increased from 7.72 on day 2 to 23.52 on day 3. This marked the onset of visible color change and the FI reached full blue by day 7. Headspace solid-phase microextraction (HS-SPME) and gas chromatography–flame ionization detection (GC-FID) quantified monomethylamine (MMA), dimethylamine (DMA) and TMA throughout storage. ΔE correlated strongly with total bacterial count (TBC, r = 0.978), pH (r = 0.901) and TMA (r = 0.888). These results indicate that microbial growth, alkalinity increase and amine production were closely associated with color transitions. The FI reliably tracked freshness loss in skate sashimi. It has potential to enhance consumer transparency and strengthen quality control in the seafood supply chain.