Objective. To clarify the effect ofLactobacillus plantarum299v on the salivary cortisol and salivary IgA levels in young adults under examination stress.Design. Forty-one students with an upcoming academic exam were included in a randomized double-blind, placebo-controlled study. The probiotic bacteria or the placebo product was administered in capsules once a day during 14 days. Saliva was collected and a perceived stress test was filled out at each sampling occasion. Saliva was collected for cortisol analysis by Electrochemiluminescence Immunoassay (ECLI) and salivary IgA was analysed by Enzyme-Linked Immunosorbent Assay (ELISA). Abundance of lactobacilli was evaluated by cultivation of saliva on selective medium and identification ofL. plantarum299v was done on randomly selected colonies by a random amplification of polymorphic DNA (RAPD) typing.Results. A significant difference in cortisol levels was found between the treatment group and the placebo group (P<0.05), together with a significant increase in levels of lactobacilli in the treatment group compared with the placebo group (P<0.001). No significant changes were found for salivary IgA.Conclusion. A probiotic bacterium with ability to reduce symptoms of irritable bowel syndrome (IBS) prohibited increased levels of the stress marker cortisol during the examination period. The registration number of the study isNCT02974894, and the study is registered at ClinicalTrials.gov.

In this work, we investigated lipid oxidation of cod liver oil during gastrointestinal (GI) digestion using two types of in vitro digestion models. In the first type of model, we used human GI juices, while we used digestive enzymes and bile from porcine origin in the second type of model. Human and porcine models were matched with respect to factors important for lipolysis, using a standardized digestion protocol. The digests were analysed for reactive oxidation products: malondialdehyde (MDA), 4-hydroxy-trans-2-nonenal (HNE), and 4-hydroxy-trans-2-hexenal (HHE) by liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC/APCI-MS), and for free fatty acids (FFA) obtained during the digestion by gas chromatography-mass spectrometry (GC-MS). The formation of the oxidation products MDA, HHE, and HNE was low during the gastric digestion, however, it increased during the duodenal digestion. The formation of the oxidation products reached higher levels when digestive juices of human origin were used (60 μM of MDA, 0.96 μM of HHE, and 1.6 μM of HNE) compared to when using enzymes and bile of porcine origin (9.8, and 0.36 μM of MDA; 0.16, and 0.026 μM of HHE; 0.23, and 0.005 μM of HNE, respectively, in porcine models I and II). In all models, FFA release was only detected during the intestinal step, and reached up to 31% of total fatty acids (FA). The findings in this work may be of importance when designing oxidation oriented lipid digestion studies.

The formation of malondialdehyde (MDA), 4-hydroxy-2-hexenal (HHE), 4-hydroxy-2-nonenal (HNE), and 4-oxo-2-nonenal (ONE) in cod liver-, anchovy-, krill-, and algae oil during in vitro digestion with human gastrointestinal fluids was investigated. Adding rabbit gastric lipase, lipase inhibitor (orlistat) and tocopherols to cod liver oil, lipolysis and oxidation was also studied. Among the marine oils, the highest aldehyde levels (18 µM MDA, 3 µM HHE and 0.2 µM HNE) were detected after digestion of cod liver oil, while the lowest levels were detected in krill and algae oils. Addition of rabbit gastric lipase significantly increased the release of HNE during the digestion. Orlistat significantly reduced lipolysis and MDA formation. Formation of MDA and HHE was delayed by tocopherols, the tocopherol mix Covi-ox® T 70 EU being more effective than pure α-tocopherol.

Efficient recycling and upcycling strategies to retain the material in the economy and away from the ecosystems are important to achieve a sustainable plastic system. Poly(butylene adipate-co-terephthalate) (PBAT) is a biodegradable polyester that has gained considerable interest for various applications. Here, we report a study on enzymatic depolymerization of PBAT, recovery and purification of its monomers, and feasible routes for their recycling/upcycling. PBAT films (15 g L⁻¹) were completely hydrolysed employing a leaf-branch compost cutinase variant (LCC-WCCG, 1.4 mg per gram polymer) to its monomers at a rate of 0.49 g L⁻¹ h⁻¹. LCC-WCCG kinetics were superior to that of other enzymes engineered for PBAT hydrolysis; the data were supported by in silico investigations. The released monomers were separated using membrane filtration and precipitation techniques and recovered with purity exceeding 95%. To close the loop, the monomers were re-polymerized and successfully cast into PBAT films. Moreover, adipic acid was reacted with hexamethylene diamine using Novozym®435 to form a polyamide, while 1,4-butanediol was oxidized to 4-hydroxybutyrate using Gluconobacter oxydans cells. The current study exemplifies a high-impact scientific approach toward a circular plastics economy.

Protein was recovered from five varieties and a mixed blend of cold-pressed rapeseed press cake by leaching and precipitation in a water-based process, and the protein recovery yield varied from 26–41% depending on variety. Exposure for heat during protein recovery severely reduced the rapeseed proteins’ ability to stabilize the oil–water interface of emulsion droplets. Protein extract from Lyside had the best emulsifying properties of the varieties investigated. Oxidation rate was assessed by the Thiobarbituric Acid Reactive Substances (TBARS) method and rapeseed protein extracts from Epure and Festivo had higher capacity to delay oxidation compared with soy lecithin. There are possibilities to broaden the use of rapeseed whereby recovered rapeseed protein can be used as a plant-based multifunctional ingredient with emulsifying capacity and which has a delaying effect on oxidation.

Marine long-chain polyunsaturated fatty acids (LC n-3 PUFA) are associated with reduced risk for inflammatory diseases, such as cardiovascular diseases and rheumatoid arthritis. These fatty acids, however, are rapidly oxidized, generating highly reactive malondialdehyde (MDA), 4-hydroxy-2-hexenal (HHE) and 4-hydroxy-2-nonenal (HNE). These oxidation products may interact with DNA and proteins, thus possibly leading to impaired cell functions. Little is known about the formation of MDA, HHE and HNE in fish oil in the gastrointestinal (GI) tract. In this study, the effect of dynamic in vitro digestion of cod liver oil on the generation of MDA, HHE and HNE was evaluated using the TNO Gastro-Intestinal Model (tiny-TIM). Effects of pre-formed oxidation products, pre-emulsification of the oil, and addition of oxidants (EDTA and hemoglobin, Hb) on GI oxidation were evaluated. Formation of aldehydes occurred during GI digestion. However, only emulsified oil fortified with 11.5 μM Hb oxidized to a degree that overcame the dilution induced by gastric secretion, which caused increased aldehyde concentrations in gastric lumen up to 90 min. The maximum levels of aldehydes generated in this study were 24.5 μM MDA, 1.6 μM HHE and 0.07 μM HNE. Oils containing different amounts of pre-formed lipid oxidation products maintained the same oxidation ranking order during digestion, even though the relative changes were not directly proportional. Emulsification of the oil had an unclear effect in the gastric phase, but a pro-oxidative effect in the intestinal phase. In general, higher aldehyde levels were reached in the intestinal lumen than in the initial meal, demonstrating that GI digestion promotes oxidation. Hence, epithelial cells may be exposed to elevated amounts of reactive aldehydes for several hours after a meal containing fish oil.