The Effect of Different Freshness of Raw Material on Lipid Quality and Sensory Acceptance of Canned Sardines.

We studied how storing fresh sardines (Sardina pilchardus) on ice for 0−15 days would affect lipid quality and sensory acceptance after the sardines were later canned. Average moisture and diacylglycerol contents showed a decreasing trend during storage time for sardines stored for to 0−10 days and an increasing trend for samples stored for 13−15 days. Total lipid and triacylglycerol average values increased with storage time of 0−10 days. In contrast, sardines stored for 13−15 days showed decreased values of lipids and triacylglycerols. Increased storage times also led to increased average saturated fatty acid (STFA) content and browning and decreased polyunsaturated fatty acid (PUFA) values and PUFA/STFA and ω3/ω6 ratios. Notably, the effect of storage time on PUFA/STFA and ω3/ω6 ratios and browning development was found significant (p < 0.05). Sensory descriptors revealed only slight quality differences with previous storage on ice for 0-10 days. In contrast, a substantial (p < 0.05) decrease (appearance and texture) was detected in samples corresponding to a 13−15-day period, such samples being considered unacceptable. Storage on ice not exceeding 10 days is recommended for sardines before being shipped to canneries for further processing. Furthermore, the use of efficient storage including preserving technologies would be desirable.

Rapid monitoring of heat-accelerated reactions in vegetable oils using direct analysis in real time ionization coupled with high resolution mass spectrometry.

Transmission-mode direct analysis in real time ionization coupled with high resolution mass spectrometry (TM-DART-HRMS) was used to monitor chemical changes in various vegetable oils (olive, rapeseed, soybean and sunflower oil) during their thermally-induced oxidation. This novel instrumental approach enabled rapid fingerprinting of examined samples and detection of numerous sample components, such as triacylglycerols (TAGs), phytosterols, free fatty acids (FFA), and their respective oxidation products. Mass spectra obtained from DART were processed with the use of principal component analysis (PCA) in order to assess the compositional differences between heated and non-heated samples. Good correlation was observed between the normalized intensities of the pre-selected ion corresponding to mono-oxidized TAG and 'classic' criterion represented by the levels of TAG polymers determined by high performance-size exclusion chromatography with refractometric detection (HP-SEC-RID).