There is a growing interest in a more wholesome utilization of biomass as the need for greener chemistry and non-mineral oil-based products increases. Lignin is the largest renewable resource for aromatic chemicals, which is found in all types of lignocellulosic biomass. Steam-explosion of lignocellulosic biomass is a useful pretreatment technique to make the polymeric material more available for processing. However, this heat-based pretreatment is known to result in the formation of pseudo-lignin, a lignin-like polymer made from carbohydrate degradation products. In this work, we have analyzed steam-exploded birch with a varying severity factor (3.1–5.0) by pyrolysis–gas chromatography–mass spectrometry, 2D-NMR, and Fourier transform infrared spectroscopy. The main results reveal a consumption of acetic acid at higher temperatures, with the increase of furan components in the pyrolyzate. The IR and NMR spectral data support these results, and there is a reason to believe that the conditions for humin formation are accomplished under steam explosion. Pseudo-lignin seems to be a humin-like compound.

The fatty acid profiles of wild and farmed Atlantic salmon (Salmo salar) and salmon feed was elucidated and quantitated. Due to the increasing proportion of vegetable oils in salmon feed, it was of interest to evaluate the effects on the farmed salmon fatty acid profile. There was found to be four times more fat in the muscle in farmed compared to wild salmon, 8.97 ± 0.63% and 2.14 ± 0.32%, respectively. The contents of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids were 15.0%, 55.4%, and 29.6%, respectively, in farmed salmon, while 26.3%, 47.4%, and 26.3% in wild salmon. The lipids were also fractioned into neutral lipids, free fatty acids, and polar lipids by solid‐phase extraction. Both wild and farmed salmon contained approximately equal amount of eicosapentaenoic acid and docosahexaenoic acid with 520 and 523 mg/100 g fish muscle, respectively. The salmons of both kinds were evaluated from a health perspective by discussing the contents of n‐3 and n‐6 fatty acids, saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids together with nutritional quality indices. In conjunction with a lower fat intake by consumption, the wild Atlantic salmon displayed the most nutritionally beneficial profile.