The Influence of Flaxseed Oil Cake Extract on Oxidative Stability of Microencapsulated Flaxseed Oil in Spray-Dried Powders

Effect of microencapsulation on physical properties of powder developed from blended oils rich in PUFA

Microencapsulation of oil samples such as flaxseed oil, blended oils such as flaxseed-sesame oil and flaxseed-rice bran oil rich in omega-3 and omega-6 fatty acids was carried out through spray drying technique. During this study, emulsions were prepared and homogenized at 1000 rpm to prepare the stable emulsion. About 8% (w/w) of oils were encapsulated with maltodextrin as wall material and Tween 20 as an emulsifier, yielding a polyunsaturated fatty acid (PUFA) microencapsulated oil powder. The physical properties of powders were calculated based on the bulk density and tapped density observations. Apart from these, Carr's index (C) and Hausner's ratio evaluated to study the flow properties of microencapsulated powders ranged between 30 and 39 for Carr's index and 1.40-1.64 for Hausner ratio, respectively. The results of moisture content stated that oil-encapsulated powders exhibited higher shelf life due to lower moisture content values of 2-4%. Encapsulation efficiency of 73%, 60%, and 80% was achieved for flaxseed oil powder, flaxseed-sesame oil powder, and flaxseed-rice bran oil powder, respectively. Powders high in PUFA such as omega-3 and omega-6 are beneficial for addressing variety of health issues, that can be used most convenient way to receive important nutrients in our period of health issues.

Improving the storage and oxidative stability of essential fatty acids by different encapsulation methods; a review

Linoleic acid and α-linolenic acid are the only essential fatty acids (EFAs) known to the human body. Other fatty acids (FAs) of the omega-6 and omega-3 families originate from linoleic acid and α-linolenic acid, respectively, by the biological processes of elongation and desaturation. In diets with low fish consumption or vegetarianism, these FAs play an exclusive role in providing two crucial FAs for maintaining our body's vital functions; docosahexaenoic acid and arachidonic acid. However, these polyunsaturated FAs are inherently sensitive to oxidation, thereby adversely affecting the storage stability of oils containing them. In this study, we reviewed encapsulation as one of the promising solutions to increase the stability of EFAs. Accordingly, five main encapsulation techniques could be classified: (i) spray drying, (ii) freeze drying, (iii) emulsification, (iv) liposomal entrapment, and (v) other methods, including electrospinning/spraying, complex coacervation, etc. Among these, spray drying was the frequently applied technique for encapsulation of EFAs, followed by freeze dryers. In addition, maltodextrin and gum Arabic were the main wall materials in carriers. Paying attention to industrial scalability and lower cost of the encapsulation process by the other methods are the important aspects that should be given more attention in the future.

Spray-Drying Impact the Physicochemical Properties and Formation of Maillard Reaction Products Contributing to Antioxidant Activity of Camelina Press Cake Extract

Spray-drying is one of the most popular techniques in the food industry for converting liquid material from a fluid state into a form of dried particles to produce encapsulated or instant products. Instant products are considered as convenient foods; moreover, the goal of encapsulation is to close the bioactive compounds in a shell, preventing them from being affected by environmental factors. The purpose of this study was to examine the influence of spray-drying conditions, in particular three inlet temperatures, on the physicochemical and antioxidant properties of powders obtained from Camelina Press Cake Extract (CPE). The CPE was spray-dried at 140 °C, 160 °C and 180 °C. The solubility, Carr and Hausner Indexes, tapped densities and water activity of the powders were analyzed. The structural changes were also detected using FTIR spectroscopy. Additionally, the characteristics of the initial and reconstituted samples and their rheological properties were evaluated. The antioxidant potential, total polyphenols and flavonoids content, free amino acids, and the Maillard reaction products contents in the spray-dried powders were also evaluated. The results indicate a cascade of changes between the initial and reconstituted samples, and important changes in the bioactive potential of samples. The inlet temperature significantly influenced the solubility, flowability and particle sizes of the powders, as well as Maillard products formation. The results of the rheological measurements illustrate the changes after the reconstitution of extracts. This study indicates the optimal parameters of CPE spray-drying, those that yield favorable physicochemical and functional values, which may open up a promising path for CPE valorization, indicating its potential and the possibilities of its use.

Effect of Flaxseed Oil Cake Extract on the Microbial Quality, Texture and Shelf Life of Gluten-Free Bread

Extending the shelf life of gluten-free bread (GFB) is a challenge. Mainly due to the ingredients used and their characteristics, GFB has numerous drawbacks such as unsatisfactory texture and rapid staling beyond a low nutritional value. In the present study, flaxseed oil cake extract (FOCE) was used to replace water (25-100%) in GFB formulations in order to test FOCE's potential to reduce GFB staling and extend microbial stability. Texture (TPA test), water activity (LF NMR), acidity (pH measurements) and microbiological quality of GFBs were tested. Moreover, the content of a lignan with broad health-promoting potential, secoisolariciresinol diglucoside (SDG), in GFB with FOCE was analyzed. The results showed that the use of FOCE enriched experimental GFB in valuable SDG (217-525 µg/100 g DM) while not causing adverse microbiological changes. A moderate level (25-50%) of FOCE did not change the main texture parameters of GFB stored for 72 h, the quality of which was comparable to control bread without FOCE. Meanwhile, higher proportions of FOCE (75-100% of water replacement) shortened GFB shelf life as determined by water activity and texture profile, suggesting that GFB with FOCE should be consumed fresh. To summarize, FOCE at moderate levels can add value to GFBs without causing a drop in quality, while still fitting in with the idea of zero waste and the circular economy.

Composition and Antioxidant Ability of Extract from Different Flaxseed Cakes and Its Application in Flaxseed Oil

In this research, extracts from five flaxseed cakes (hot-pressed cake (HPC), cold-pressed cake (CPC), n-hexane extracted cake (HEC), supercritical CO₂ extracted cake (SCEC) and subcritical n-butane extracted cake (SBEC)) were analyzed for the contents of total phenolic, total flavonoid and antioxidant ability. At the same time, the antioxidant capacity of HPC extract and synthetic butylated hydroxyanisole (BHA) in the oxidative evolution of flaxseed oil was compared by accelerated storage experiment (8 days at 65°C). The results showed that compared with other flaxseed cake extract, the extract of HPC contained the highest content of total phenolic (78.01 mg GAE/g extract) and total flavonoid (2.73 mg RE/g extract), and showed the strongest antioxidant ability on DPPH, ABTS FRAP and total reducing power assay. We also found that different concentrations (800, 1000, 2000 ppm) of flaxseed cake extract could significantly slow down the oxidation of flaxseed oil during storage at 65°C, and the antioxidant effect strengthened with the increase of extract dosage. The antioxidant effect of the 2000 ppm extract was higher than that of 200 ppm BHA. The results indicated that flaxseed cake extract could effectively inhibit the oxidation of flaxseed oil and was a good substitute for synthetic antioxidants in oil industry.

Novel Gluten-Free Bread with an Extract from Flaxseed By-Product: The Relationship between Water Replacement Level and Nutritional Value, Antioxidant Properties, and Sensory Quality

The food industry generates a great amount of food waste and by-products, which in many cases are not fully valorized. Press cakes, deriving from oilseeds extraction, represent interesting co-products due to their nutritional value, high biopolymers content, and the presence of bioactive phytochemicals. Gluten-free breads (GFBs) are products that have disadvantages such as unsatisfactory texture, low nutritional value, and short shelf life, so natural additives containing proteins and hydrocolloids are in demand to increase GFBs value. In this study, extract from flaxseed by-product (FOCE-Flaxseed Oil Cake Extract) was used to replace water (25-100%) in GFBs formulations and their nutritional value, antioxidant properties, and sensory features were investigated. The results showed that GFBs with FOCE had an elevated nutritional and nutraceutical profile (up to 60% more proteins, significantly increased K, Mg, and P levels). Moreover, the addition of FOCE improved the technological parameters (increased specific volume, number of cells and height/width ratio, reduced density, average size, and perimeter of cells), antioxidant potential, and overall sensory quality of GFBs. This study showed an encouraging way of using a by-product that, due to its high content of proteins, polysaccharides, minerals, and antioxidants, can add value to GFBs.

Production and Characterization of Yogurt-Like Fermented Beverage Based on Camelina (Camelina sativa L.) Seed Press Cake

Plant-based fermented beverages are growing in popularity due to the rise in vegetarianism, health trends and ethical concerns. In this study, camelina (Camelina sativa L.) seed press cake (CPC, 15% and 20% w/w) was fermented using yogurt starter culture. The physicochemical properties of the samples, including pH, total acidity, color, viscosity, texture and rheological properties were investigated. Moreover, the lactic acid bacteria (LAB) viability, bioactive compounds and antioxidant activity were determined. During fermentation and 28-day refrigerated storage, the samples achieved a mean viable bacterial count of at least 1010 CFU/g, which is higher than the recommended bacteria level for traditional dairy yogurt (106 CFU/g). A significant acidification, consumption of reducing sugars, increase in free amino acids and polyphenolics was observed. In addition, CPC-based fermented samples showed good antioxidant potential. Textural and rheological characteristics were similar to dairy yogurt. Moreover, fermentation improved the sensory attributes of CPC, meeting consumers’ acceptance criteria. Thus, the study indicated that fermentation had a marked effect on the physicochemical, microbiological and functional properties of CPC. Therefore, the fermented CPC-based beverage has the potential to be a valid, value-added and novel alternative to dairy-based yogurt.

Innovative and Sustainable Technologies to Enhance the Oxidative Stability of Vegetable Oils

To meet consumers’ demand for natural foods, edible oil producers and food processing industries are searching for alternatives to synthetic antioxidants to protect oils against oxidation. Antioxidant compounds extracted from different plant parts (e.g., flowers, leaves, roots, and seeds) or sourced from agri-food industries, including residues left after food processing, attract consumers for their health properties and natural origins. This review, starting from a literature research analysis, highlights the role of natural antioxidants in the protection of edible oils against oxidation, with an emphasis on the emerging and sustainable strategies to preserve oils against oxidative damage. Sustainability and health are the main concerns of food processing industries. In this context, the aim of this review is to highlight the emerging strategies for the enrichment of edible oils with biomolecules or extracts recovered from plant sources. The use of extracts obtained from vegetable wastes and by-products and the blending with oils extracted from various oil-bearing seeds is also pointed out as a sustainable approach. The safety concerns linked to the use of natural antioxidants for human health are also discussed. This review, using a multidisciplinary approach, provides an updated overview of the chemical, technological, sustainability, and safety aspects linked to oil protection.

The Application of Spray-Dried and Reconstituted Flaxseed Oil Cake Extract as Encapsulating Material and Carrier for Probiotic Lacticaseibacillus rhamnosus GG

Agro-industrial by-products are promising source of biopolymers, including proteins and polysaccharides. This study was designed to evaluate the flaxseed oil cake extract (FOCE) as natural encapsulating material and carrier for probiotic Lacticaseibacillus rhamnous GG (LGG). The powders were obtained using three spray drying inlet temperatures (110 °C, 140 °C, 170 °C), and reconstituted. The influence of temperature on water activity, morphology, chemical composition, flowability and cohesiveness of the powders was estimated. For all variants, the survival of bacteria during spray drying, and simulated passage through the gastrointestinal tract was evaluated. The preservation of LGG probiotic features such as cholesterol reduction, hydrophobicity and adhesion to mucin were examined. Results revealed that all physicochemical and functional characteristics of the powders were affected by the inlet temperature. This study demonstrated that FOCE is an appropriate matrix for spray drying (due to flaxseed proteins and polysaccharides) providing high survivability of bacteria (89.41-96.32%), that passed meaningfully through the simulated gastrointestinal tract (4.39-5.97 log reduction), largely maintaining their probiotic properties, being a promising environmentally-friendly carrier for probiotic LGG.