Combining untargeted, targeted and sensory data to investigate the impact of storage on food volatiles: A case study on strawberry juice.

An integrated science-based approach, combining analytical and sensorial data and different data analysis methods, proved successful to study the impact of storage time, storage temperature and oxygen availability on strawberry juice volatiles and allowed to get a multi-perspective view on these changes. An untargeted GC-MS approach showed that the volatile fraction of shelf-stable strawberry juice clearly changed during ambient storage and that oxygen availability (linked to the type of bottle) had a limited effect. To gain further insight, several characteristic aroma compounds were quantified during storage at ambient (20 °C) and accelerated (28-42 °C) temperatures, kinetic parameters were estimated and odour activity values were calculated. The kinetic parameters showed that all characteristic aroma compounds changed significantly during storage at all temperatures and that the rate of change in some compounds was accelerated by storage at higher temperatures. The observed changes in strawberry juice volatiles caused sensorial differences between non-stored and 20 °C stored samples as shown by the sensory evaluations and odour activity values.

Multitrait analysis of fresh-cut cantaloupe melon enables discrimination between storage times and temperatures and identifies potential markers for quality assessments.

Fresh-cut cantaloupe melon is valued for its aroma but is highly perishable. Temperature of storage (typically 0-5°C) is critical for maintaining fresh-cut melon quality, but often reaches 10°C during transportation and in retail outlets. A comparison amongst 0, 5 and 10°C storage temperatures for fresh-cut melon over 14days reveals that storage at 0°C is optimal for avoiding increases in microbial load and loss of vitamin C especially at later time points. However, higher temperatures maintain better the balance of esters (acetate versus non-acetate) and phenolic content. The whole volatile organic compound (VOC) profile can be used to discriminate both time and temperature effects especially at earlier time points. Potential VOC markers for changes in vitamin C from day 0 to day 6 of storage (3-methyl butane nitrile) and temperature (limonene) are identified through a multi-trait analysis.

The profile of volatile compounds in the outer and inner parts of broiled pork neck is strongly influenced by the acetic-acid marination conditions.

Raw pork neck cutlets were marinated in an aqueous solution of acetic acid (pH4, 24h, 4°C) without (M) or with 1% (w/w) of glucose. The control (K) was formed by non-treated raw pork neck. The cutlets were then broiled (185°C, 30min). In all K cutlets, significant higher amounts of volatile compounds (VCs) were developed after broiling than the other samples. Significant more aldehydes and alcohols were present in the inner parts than in the surface. The correlation between surface and internal layers was high only for aldehydes. Marinating decreased the differences among VCs and led to the standardization of the processed meat. The addition of glucose to the marinade led to more volatile aldehydes, carboxylic acids, esters, furan, pyran, pyrazine, pyrrol and pyridine derivatives than in M samples. Several (53) specific VCs explained the differences among the surface samples related to the marinating process. However, only 16 VCs explained the variance among the inner parts.