Long-term quality assessment of the vacuum-sealed salted and honey-roasted peanuts after 30 years of storage based on lipid stability, volatile compounds, and olfactory characteristics.

The long-term stability of vacuum-sealed food products remains a theoretically explored but critical aspect in shelf-life prediction and food security. This study investigated the chemical and sensory quality of vacuum-sealed roasted peanuts stored in tinplate cans for an unprecedented 30-year period, comparing two commercial products, salted and honey-roasted peanuts, manufactured in 1993 and 2024. The study aimed to elucidate whether properly vacuum-sealed roasted peanuts can retain lipid stability, flavor quality, and consumer acceptability over extended storage durations. After three decades of ambient storage, the vacuum levels in all cans remained intact, and no significant lipid oxidation was observed, as evidenced by stable levels of conjugated diene hydroperoxides (CDHP), thiobarbituric acid reactive substances (TBARS), acid values (AV < 4 mg KOH/g oil), and fatty acid composition. However, when the vacuum was intentionally broken and samples were stored at 60 °C for 6 weeks to simulate abusive post-opening conditions, a rapid increase in AV was observed. GC-MS analysis revealed elevated levels of aldehydes, ketones, and alcohols alongside reduced pyrazine contents, resulting in rancid off-flavors. Partial least squares regression (PLSR) analysis showed that Maillard-derived volatiles positively correlated with honey, roasted, and salty odors and overall odor acceptability. In contrast, secondary lipid oxidation products such as 2-decanone, nonanal, and trans-2-decenal were negatively correlated with acceptability and linked to rancid or fatty odors. This study provides novel evidence that roasted peanuts, when sealed under vacuum in tinplate cans, can retain chemical and sensory stability for at least three decades under ambient conditions. These findings not only underscore the significance of vacuum packaging for long-term food preservation but also identify volatile markers useful for quality assessment in stored lipid-rich foods.