Filters
Protein fractions from flaxseed: the effect of subsequent extractions on composition and antioxidant capacity
Flaxseed proteins exhibit functionalities interesting for the food industry, including antioxidant capacity. Antioxidant activity depends on the protein composition and the presence of phenolic compounds extracted with them from the matrix. The research focused on the effect of subsequent protein extractions (water, salt and alkaline) of flaxseed meals (of three cultivars) on the protein fraction composition and its relations to antioxidant capacity. The protein and phenolic profiles and antioxidant functionalities (in antiradical ORAC and emulsion assays) were analysed. Spectroscopic characteristics of the fractions (fluorometric and FT-IR analysis) were also included. Our study has shown the effect of fractionation on the share of proteins at MW from 56–38 kDa (globulin-like) and <15 kDa (albumin-like) in the protein profiles. The highest globulin share was in the alkaline-extracted fractions (AEF) and albumin in the salt-extracted (SEF) ones. SDG (secoisolariciresinol diglucosides) and phenolic acids (p-coumaric and ferulic) were extracted with flaxseed proteins. Their contents were fraction-dependent and the highest in AEF. The concentration of phenolics in AEF corresponded with the highest antiradical capacity (ORAC) compared with the other fractions. However, the SEF showed a higher ability to inhibit oxidation in emulsions than AEF, which could be associated with the higher content of the low MW proteins.
Flaxseed (Linum usitatissimum L.) protein and peptide identification of raw and roasted seeds: application of the UHPLC-Q-TOF-MS/MS method
AbstractBACKGROUNDFlax (Linum usitatissimum L.) seeds are in the spotlight due to their enormous potential as a functional food ingredient, and proteins and peptides play a crucial role in their functional food properties. Flax seeds can be added to foods during production either before or after heat pre‐treatment (roasting), creating the need for thermally stable peptides as markers for flax seed identification. In this study, the proteins of untreated and roasted seeds of three flax cultivars (Jantarol, Oliwin and Szafir) were analyzed by high‐resolution tandem mass spectrometry coupled to high‐performance liquid chromatography (UHPLC‐Q‐TOF‐MS/MS) to search for species‐specific peptides as potential markers of flax seeds.RESULTSTwenty‐three proteins found in untreated seeds of each cultivar were selected using UHPLC‐Q‐TOF‐MS/MS. After roasting, six of them were identified based on 13 unique and species‐specific peptides, and they have been suggested as potential thermally stable species‐specific markers for the identification of flax seed proteins. Among them, one new unique and thermally stable peptide, DPVLAWR, was found that had not been identified in previous studies.CONCLUSIONOur research has provided novel information on the protein and peptide identification of flax seeds taking into account possible cultivar diversity. In the study, the proteomics UHPLC‐Q‐TOF‐MS/MS method was applied. In addition, heat‐stable peptides were determined as a potential indicator for the identification of flax seeds after roasting, a process often used for oilseed pre‐treatment. © 2025 Society of Chemical Industry.
Changes in physicochemical, textural, and sensorial properties of pork meatballs made with the addition of hemp oil during storage
This research aimed to evaluate the quality characteristics of cooked and vacuum-packed meatballs reformulated with cold-pressed hempseed oil as a partial pork substitute (0.8%, 2.5%, 4.2%, and 7.5%) during 12 days of storage. The water activity, cooking, and storage losses increased with a higher content of hemp oil ( P < 0.05). The total saturated fatty acids were reduced by 37.6%, whereas the polyunsaturated fatty acids content improved by 96.1%. Hemp oil addition decreased protein and lipid oxidation during the storage period ( P < 0.05). The inhibition effect on carbonyl content reached 34.9% and on TBARS values reached 17.5%. Sensory analysis revealed no significant changes to the texture, odour, and taste attributes over 12 days of storage in vacuum packaging. The results indicate that cold-pressed hemp oil can be an alternative ingredient for the production of meat products with improved nutritional value, particularly by enriching them with n-3 α-linolenic fatty acid.