Changes of bioactive components in berry seed oils during supercritical CO2 extraction

The objective of the work was to elucidate the chemical composition of fractions of oil extracts obtained during the supercritical extraction on a semi‐industrial scale from strawberry (Fragaria x ananassa Duch.), chokeberry [Aronia melanocarpa (Michx.)], and raspberry (Rubus idaeus L.) seeds from industrial press cake. The oil extracts differed in terms of their content of bioactive components: carotenoids, tocopherols, chlorophylls, and fatty acids. Raspberry seed oil was the richest source of tocopherols (620.1–2166.7 mg kg^?1) and α‐linolenic acid (above 37%). Chokeberry seed oil had the highest content of linoleic acid (above 70%), and α‐tocopherol (166.0–1104.8 mg kg^?1). Strawberry oil was characterized by the highest content of chlorophylls and α‐linolenic acid (above 30%). It was showed that the oil fraction collected at the beginning of extraction is characterized by a high acid value, which requires purification steps to be used for food purposes.

Practical applications

Strawberry, raspberry, and chokeberry by‐products left over from the production of concentrated juice are a valuable source of oils rich in n‐3 and n‐6 polyunsaturated fatty acids, tocopherols, and carotenoids. The research showed that the fractionation of extracts in the course of supercritical extraction leads to oils with varying amounts of different bioactive compounds, and thus to products with potentially wide applications. Seeds oils have high potential utility as a source of unconventional oil for cosmetic and pharmaceutical sectors and biodiesel. Their targeted utilization may be exploited for economic, environmental and health benefits.     

Lecane tenuiseta rotifers improves activated sludge settleability in laboratory scale SBR system at 13°C and 20°C

Two experiments at different temperatures were conducted in five laboratory‐scale bioreactors with enhanced nutrient removal simulating the work of sequencing batch reactors (SBRs). The process was operated in three 8‐hour cycles. The oxygen concentration, pH and temperature were controlled and maintained at 1 mg of O₂/L, 7 and 13°C, respectively, throughout the first two weeks and at 20°C for the next 10 days. The introduction of Lecane tenuiseta improved the settling properties of the activated sludge dominated by Microthrix parvicella at both temperatures tested. L. tenuiseta rotifers led to a reduction in filamentous bacteria abundance and did not negatively affect the chemical parameters of the effluent. For each temperature, there were no differences in COD, N_tot, N‐NH₄ or P‐PO₄ values between the treatment and control bioreactors. The results have shown that the application of L. tenuiseta is a promising biological tool for bulking prevention especially in a cold season.