Fatty Acid Profile, Total Phenolic Content, and Antioxidant Activity of Niger Seed (Guizotia abyssinica) and Linseed (Linum usitatissimum)

Defatted Flaxseed Flour as a New Ingredient for Foodstuffs: Comparative Analysis with Whole Flaxseeds and Updated Composition of Cold-Pressed Oil

BACKGROUND

Flaxseeds are functional foods popular in current diets. Cold-pressing is a solvent-free method to extract flaxseed oil, resulting in a by-product-defatted flour.

OBJECTIVES/METHODS

This study compared whole flaxseeds and defatted flour (proximate composition, fatty acids, vitamin E, total phenolics and flavonoids, antioxidant activity, amino acids, and protein quality) and updated the composition of cold-pressed oil (oxidative stability, peroxide value, UV absorbance, colour, fatty acids, vitamin E, total phenolics and flavonoids, and antioxidant activity) to assess the nutritional relevance and potential for food applications of these samples.

RESULTS

The flour had higher ash (6% vs. 4%), fibre (36% vs. 34%), protein (28% vs. 16%), phenolics (205 vs. 143 mg gallic acid equivalents/100 g), and antioxidant activity than seeds (p < 0.05), so it should be valued as a novel high-fibre food ingredient with high-quality plant-based protein, as it contains all essential amino acids (106 mg/g) and a high essential amino acids index (112%), with L-tryptophan as the limiting amino acid. The oil, while low in oxidative stability (1.3 h), due to its high polyunsaturated fatty acids sum (75%), mostly α-linolenic acid (57%), contains a significant amount of vitamin E (444 mg/kg), making it a specialty oil best consumed raw.

CONCLUSIONS

The exploration of the flour as a minimally processed food ingredient highlights its role in supporting food security, circular economy, and sustainability goals, aligning with consumer preferences for natural, low-fat foods. Future research should investigate the bioactivity and shelf-life of the samples, as well as the bioavailability of compounds after digestion.

Comparative Analysis of Grape Seed Oil, Linseed Oil, and a Blend: In Vivo Effects of Supplementation

Grape seeds are rich in bioactive substances, including polyphenols, terpenoids, and phytosterols. Linseed (Linum usitatissimum L.) boasts a high concentration of polyunsaturated fatty acids (PUFAs), lignans, phytoestrogens, and soluble fibers, all contributing to its therapeutic potential. In this study, we pioneered the formulation of an oil blend (GL) combining grape seed oil (G) and golden linseed oil (GL) in equal volumes (1:1 (v/v)) and we evaluated in terms of the nutritional, physical, and chemical properties and their influence in an in vivo experimental model. We analyzed the oils by performing physical-chemical analyses, examining the oxidative stability using Rancimat; conducting thermal analyses via thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC), performing optical UV-vis absorption analyses; examining the fluorescence emission-excitation matrix, total carotenoids, and color, and conducting metabolic assessments in an in vivo experimental trial. The fatty acid profile presented a higher fraction of linoleic acid (C18:2) in G and GL and alpha-linolenic acid (C18:3) in L. The acidity and peroxide indices were within the recommended ranges. The TG/DTG, DSC, and Rancimat analyses revealed similar behaviors, and the optical analyses revealed color variations caused by carotenoid contents in L and GL. In the in vivo trial, G (G2: 2000 mg/kg/day) promoted lower total consumption, and the blend (GL: 2000 mg/kg/day) group exhibited less weight gain per gram of consumed food. The group with G supplementation (G2: 2000 mg/kg/day) and GL had the highest levels of HDL-c. The group with L supplementation (L2: 2000 mg/kg/day) had the lowest total cholesterol level. The L2, G1 (1000 mg/kg/day), and G2 groups exhibited the lowest MCP-1 and TNF-α values. Additionally, the lowest adipocyte areas occurred in G and GL. Our results suggest that this combination is of high quality for consumption and can influence lipid profiles, markers of inflammation, and antioxidant status.

Optimizing niger seed (Guizotia abyssinica) oil quality: A comprehensive analysis of infrared-heat induced changes in bioactive profile, physiochemical attributes, and oxidative stability

Infrared heating (IRH) at 140, 160, and 180°C for varying durations (5, 10, and 15 min) was employed for improving the niger (Guizotia abyssinica) seed oil (NSO) quality for diverse food applications. The study explored changes in phenolic profile, oxidative stability index (OSI), tocopherols, phytosterols, fatty acid profiles, and physicochemical attributes of NSO. Upon IRH at 180°C for 10 min, the oil yield, total phenolic, and flavonoid contents increased from 33.09% to 40.56%, 6.67 to 173.62 mg GAE/kg, and 24.76 to 120.64 mg QE/kg, respectively. The viscosity, chlorophylls, carotenoids, radical scavenging activity, OSI, caffeic, protocatechuic, vanillic, and syringic acids were highest upon IRH at 180°C for 15 min. The tocopherols and phytosterols initially augmented while decremented upon raising IRH conditions. The infrared spectra indicated no adverse impact of IRH on NSO quality. The appropriate IRH conditions can be considered for improving NSO quality and making it valuable for various edible products.

Quality assessment of flax advanced breeding lines varying in seed coat color and their potential use in the food and industrial applications

BACKGROUND

With the increasing consumer awareness of the strong relationship between food and health, flax became a promising functional food due to its bioactive nutraceutical composition. Intra-specific crosses of eight contrasting flax genotypes were performed previously, and within segregating F6 progeny families, we investigated a close-up composition of phytochemicals derived from whole seeds.

RESULTS

The considerable genetic variation among the flax F6 families suggested that intra-specific hybridization is essential in flax breeding to obtain and broaden genetic variability and largely affirmed the opportunity for selecting promising lines. Also, significant variations in the targeted metabolite contents and antioxidant properties were observed among brown and yellow-seeded families. Notably, brown-seeded families expressed the highest average values of saturated fatty acids, protein, fiber, tocopherol, phenolics, SDG, and SECO lignans. Yellow-seeded families represented the highest average content of unsaturated fatty acids and mucilage. The cultivation year significantly affects flaxseed's composition and functional properties, presumably due to temperature, humidity, and sunshine time differences. Interestingly, the seeds obtained in warmer conditions were more potent and had more chemical constituents. The favorable genetic correlations among all evaluated traits suggest the possibility of joint genetic selection for several nutritional and phytochemical characteristics in flax. The current study highlights the importance and utilization of 19 top families as their seeds and oil play imperative roles in the pharmaceuticals and food industries. The antioxidant capacity of the seeds showed that families 84B, 23B, 35Y, 95Y, 30B, 88B, and 78B serve as a natural source of dietary antioxidants beneficial to human health. To increase the oxidative stability of the flaxseed oil, the quality evaluation identified some families with low levels of linolenic acid.

CONCLUSIONS

These findings are essential to improving flaxseed's nutritional quality and therapeutic properties through a bulk breeding program.

Comparison of nutritional quality of fourteen wild Linum species based on fatty acid composition, lipid health indices, and chemometric approaches unravelling their nutraceutical potential

Fatty acid profiles of 14 Linum species was determined by GC-MS analysis to study the nutritional quality of Linum species based on fatty acid composition, lipid health indices, and chemometric approaches. L. lewisii and L. marginale found to have the highest content of ALA i.e., 65.38 % and 62.79 %, respectively, L. tenuifolium recorded the highest linoleic acid content (69.69 %), while, L. catharticum recorded highest oleic acid (27.03 %). Health indices viz. polyunsaturated fatty acids/saturated fatty acids ratio, n-6/n-3 fatty acids ratio, atherogenicity, thrombogenicity, oxidability, oxidative stability, hypocholesterolemic/hypercholesterolemic fatty acids, and peroxidisability calculated based on the fatty acid composition revealed that all the linseed species except L. aristatum, L. tenuifolium and L. hudsoniodes have healthy fatty acid composition. L. lewisii clearly emerges as a promising species followed by L. bienne with great values across multiple indices, making them as a potential candidate for dietary or nutritional interests. The lipid profile of Linum species could be well distinguished by two principal components by Principal Component Analysis (PCA).

Novel Biodegradable Nanoparticulate Chain-End Functionalized Polyhydroxybutyrate-Caffeic Acid with Multifunctionalities for Active Food Coatings

The bioactivities of polyhydroxyalkanoates have been curtailed owing to the lack of bioactive functional groups in their backbones. In this regard, polyhydroxybutyrate (PHB) produced from new locally isolated Bacillus nealsonii ICRI16 was chemically modified for enhancing its functionality, stability as well as solubility. First, PHB was transformed to PHB-diethanolamine (PHB-DEA) by transamination. Subsequently, for the first time, the chain ends of the polymer were substituted by caffeic acid molecules (CafA), generating novel PHB-DEA-CafA. The chemical structure of such a polymer was confirmed by Fourier-transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance (¹H NMR). The modified polyester demonstrated improved thermal behavior compared to PHB-DEA as was shown by thermogravimetric analysis, derivative thermogravimetry, and differential scanning calorimetry analyses. Interestingly, 65% of PHB-DEA-CafA was biodegraded in a clay soil environment after 60 days at 25 °C, while 50% of PHB was degraded within the same period. On another avenue, PHB-DEA-CafA nanoparticles (NPs) were successfully prepared with an impressive mean particle size of 223 ± 0.12 nm and high colloidal stability. The nanoparticulate polyester had powerful antioxidant capacity with an IC₅₀ of 32.2 mg/mL, which was the result of CafA loading in the polymer chain. More importantly, the NPs had a considerable effect on the bacterial behavior of four food pathogens, inhibiting 98 ± 0.12% of Listeria monocytogenes DSM 19094 after 48 h of exposure. Finally, the raw polish sausage coated with NPs had a significantly lower bacterial count of 2.11 ± 0.21 log cfu/g in comparison to other groups. When all these positive features are recognized, the polyester described herein could be considered as a good candidate for commercial active food coatings.

In Vitro Antidiabetic, Antioxidant, and Prebiotic Activities of the Chemical Compounds Isolated from Guizotia abyssinica

India and Ethiopia employ Guizotia abyssinica (niger plant) as a source of edible vegetable oil. Previous studies have documented the niger plant's antioxidant properties and dietary benefits. Here, G. abyssinica extract was obtained and ten known bioactive components (1-10) were isolated. The antioxidant, antidiabetic, and prebiotic properties of whole extract and isolated components of niger and the plant's ability to cooperate symbiotically with probiotic strains were examined. Compound 10, myricetin-3-O-L-rhamnoside, had the highest antioxidant capacity measured in the 2,2-diphenylpicrylhydrazyl (DPPH, 4629.76 ± 6.02 µmol Trolox equivalent/g compound) and ferric-reducing antioxidant power (FRAP, 2667.62 ± 7.5 mol Trolox equivalent/g compound) assays. The lowest α-amylase and glycogen phosphorylase activities and glucose diffusion were obtained with whole G. abyssinica extracts, whereas compounds 8-10 had moderate inhibitory effects. G. abyssinica extract also induced the highest glucose absorption by yeast cells in the presence of 5 mM of glucose. Moreover, Lactobacillus plantarum and L. rhamnosus incubated with β-sitosterol 3-O-D-glucoside (compound 7) showed the highest prebiotic activity score. The levels of L-(+)-lactic acid isomer in the probiotic strains were the highest in presence of the whole extract and decreased progressively in the presence of flavonoid glycosides (compounds 8-10) and β-sitosterol 3-O-D-glucoside. The enzymatic profile of the probiotic strains was unaffected by the niger extract and compounds 7-10. The findings revealed that the biological activities of G. abyssinica extract are mediated by the compounds 1-10, and it may be considered as a promising plant for the treatment of diabetes mellitus.

Can omic tools help generate alternative newer sources of edible seed oil?

There are three pathways for triacylglycerol (TAG) biosynthesis: De novo TAG biosynthesis, phosphatidylcholine-derived biosynthesis, and cytosolic TAG biosynthesis. Variability in fatty acid composition is mainly associated with phosphatidylcholine-derived TAG pathway. Mobilization of TAG-formed through cytosolic pathway into lipid droplets is yet unknown. There are multiple regulatory checkpoints starting from acetyl-CoA carboxylase to the lipid droplet biogenesis in TAG biosynthesis. Although a primary metabolism, only a few species synthesize oil in seeds for storage, and less than 10 species are commercially exploited. To meet out the growing demand for oil, diversifying into newer sources is the only choice left. The present review highlights the potential strategies targeting species like Azadirachta, Callophyllum, Madhuca, Moringa, Pongamia, Ricinus, and Simarouba, which are not being used for eating but are otherwise high yielding (ranging from 1.5 to 20 tons per hectare) with seeds having a high oil content (40-60%). Additionally, understanding the toxin biosynthesis in Ricinus and Simarouba would be useful in developing toxin-free oil plants. Realization of the importance of cell cultures as "oil factories" is not too far into the future and would soon be a commercially viable option for producing oils in vitro, round the clock.

Characterization of persistent organic pollutants and culturable and non-culturable bacterial communities in pulp and paper sludge after secondary treatment

Due to the presence of various organic contaminants, improper disposal of pulp-paper wastewater poses harm to the environment and human health. In this work, pulp-paper sludge (PPS) after secondary treatment were collected from M/s Century Pulp-paper Mills in India, the chemical nature of the organic pollutants was determined after solvent extraction. All the isolates were able to produce lipase (6.34-3.93 U ml^-1) which could account for the different fatty acids detected in the PPS. The dominant strains were in the classes of α and γ Proteobacteria followed by Firmicutes. The Shannon-Weiner diversity indexes for phylotype richness for the culturable and non-culturable bacterial community were 2.01 and 3.01, respectively, indicating the non-culturable bacterial strains has higher species richness and diversity compared to the culturable bacterial strains. However, the culturable strains had higher species evenness (0.94 vs 0.90). Results suggested only a few isolated strains were resistant to the POPs in the PPS, where as non-cultural bacteria survived by entering viable but non-cultural state. The isolated strains (Brevundimonas diminuta, Aeromonas punctata, Enterobacter hormaechei, Citrobacter braakii, Bacillus pumilus and Brevundimonas terrae) are known for their multidrug resistance but their tolerance to POPs have not previously been reported and deserved further investigation. The findings of this research established the presence of POPs which influence the microbial population. Tertiary treatment is recommended prior to the safe disposal of pulp paper mill waste into the environment.