Producers have to guarantee the extra virgin olive oil (EVOO) quality characteristics reported in the Regulation (CEE) 2568/91 throughout the product shelf-life (SL). Unfortunately, due to the development of oxidative reactions, some quality indices change during storage leading to a progressive deterioration of EVOO quality. To avoid the risk of product downgrading in the virgin oil category, the development of effective shelf-life prediction models is extremely important for the olive oil industry. In this research, the accelerated shelf-life testing (ASLT) protocol was applied to evaluate the temperature dependence of selected oxidation indexes as well as to develop a shelf-life predictive model. The evolution of conventional (peroxide value, K232, K270, polyphenols, tocopherols and hexanal) and unconventional parameters (conjugated trienes and pyropheophytin a) was monitored in bottled EVOO stored in the dark at increasing temperature (25, 40, 50 and 60 °C). Accordingly, for well-packed products with reduced oxygen in headspace, the best shelf-life index allowing the ability to predict EVOO SL turned out to be K270. In addition, pyropheophytin a (%) has been shown to be more sensitive to temperature changes than the secondary oxidation indices, thus suggesting its use as a freshness indicator for storage temperatures higher than 25 °C.

In packed low-moisture foods such as crackers, oxidation is generally the main cause of quality depletion during storage. It is commonly believed, but scarcely investigated, that product shelf life depends on the oxidative status of the lipid ingredients. In this study, the influence of oxidation degree of the ingredient sunflower oil on cracker oxidative stability and hence shelf life was investigated. To this aim, oil with increasing peroxide values (PVs) (5, 11, and 25 mEqO₂/kg_oil) was used to prepare crackers. Just after production, crackers presented similar peroxide and rancid odor intensity, probably due to the interactive pathways of oxidative and Maillard reactions. Crackers were packed and analyzed for PV and rancid odor during storage at 20, 40, and 60 °C. Rancid odor well discriminated cracker oxidative status. Relevant oxidation rates were used to develop a shelf life predictive model based on the peroxide value of the ingredient oil. It was estimated that an oil PV from 5 to 15 mEqO₂/kg_oil shortens cracker Shelf Life (SL) by 50%, independently of storage temperature. These results demonstrate the critical impact of ingredient quality on product performance on the market.

The effect of hyperbaric storage (HS) on polyphenoloxidase activity (PPO) was studied in model solutions and apple juice. Model solutions containing increasing amounts of mushroom (Agaricus bisporus) PPO (up to 26 U) were stored at room temperature at pressure up to 200 MPa. During HS, samples were assessed for residual PPO activity. The enzyme was completely inactivated according to a first-order kinetic model that was used to calculate PPO decimal reduction time (D_p) and pressure sensitivity (z_p = 140.8 MPa) in diluted model solutions (2 U PPO). The increase in enzyme concentration (6–26 U) nullified the effect of HS, probably due to protein structure stabilization by self-crowding. The application of HS at 100 and 200 MPa to apple juice promoted a decrease in total bacteria, lactic acid bacteria, yeasts, and molds. These changes occurred in concomitance with the inactivation of PPO (z_p = 227.3 MPa). At 200 MPa, PPO inactivation followed a biphasic first-order kinetic, suggesting the presence of PPO isozymes with different pressure sensitivity. The inactivation of PPO was observed to occur more rapidly with increasing storage pressure and led to the maintenance of the original bright juice color. This study proves the capability of HS to control enzyme-related quality decay in fruit juices and, potentially, in many other food matrices suffering enzymatic alteration.

Instant coffee powder is highly sensitive to environmental humidity, which can significantly affect its quality during storage. The objective of this study was to evaluate the storage stability of instant coffee by assessing the moisture uptake and monitoring the evolution of key quality indicators under different environmental relative humidity (ERH) conditions. To this purpose, instant coffee was removed from its original packaging and stored at 11, 32, and 65% relative humidity (ERH) at 20 °C. Quality parameters related to both the powder (visual appearance and solubilization time) and the resulting brew (pH) were monitored over time. The coffee stored at 11% ERH demonstrated stability throughout the observation period. Storage at 32% ERH resulted in short-term powder stability, but a notable pH decline after six months. At 65% ERH, critical moisture levels were exceeded within one week, resulting in rapid visual degradation, impaired solubilization, and reduced brew quality within three months. The acquired findings on the behavior of a dry food powder under various storage conditions are particularly relevant in the context of the increasing application of compostable packaging with low moisture barriers, in conjunction with the need to manage the secondary shelf life of dry food powders whose use is often parceled.