Processing of natural plant raw materials and their use as additives in the food industry

The article deals with the issues of deep processing of non-traditional plant raw materials – amaranth. The authors found that amaranth seeds of various types are a source of starch and protein, balanced in amino acid composition. A comparative assessment of the main nutrients and mineral composition of amaranth seeds with traditional crops showed that amaranth seeds are unique as raw materials for the production of biologically active additives. It is proved that a fine powder of whole-ground flour is possible to obtain by double mechanical processing of amaranth seeds with mandatory heat treatment before introduction into the recipe. It was experimentally revealed that the developed biologically active additive has a high nutritional value and functional properties, which are formed due to squalene content, essential amino acids and plant phospholipids.

On the Squalene Content of CV Chondrolia Chalkidikis and Chalkidiki (Greece) Virgin Olive Oil

This work is a continuation of efforts to establish the nutritional profile of virgin olive oil (VOO) from cv. Chondrolia Chalkidikis and Chalkidiki and to strengthen its positioning in the global VOO landscape. VOOs produced at an industrial scale in different olive mills of the Chalkidiki (Greece) regional unit as well as VOOs obtained at the laboratory scale from drupes of different maturity stages for four consecutive harvesting years were examined for their squalene (SQ) content using both HPLC and GC procedures. The mean values of SQ were found to be 4228 (HPLC) and 4865 (GC) mg/kg oil (n = 15) and were of the same magnitude as that in VOOs from cv Koroneiki (4134 mg/kg, n = 23). Storage of VOOs in the dark at room temperature for 18 months indicated an insignificant mean SQ content loss (~2%) in comparison to a mean loss of 26% for alpha-tocopherol content. This finding strengthens our view that SQ does not act as a radical scavenger that donates hydrogen atoms to the latter. The four consecutive harvest years studied indicated a clear declining trend in VOO SQ concentration upon olive ripening. To our knowledge, this is the first systematic work concerning the SQ content of Chondrolia Chalkidikis and Chalkidiki VOOs.

Green Microalgae Strain Improvement for the Production of Sterols and Squalene

Sterols and squalene are essential biomolecules required for the homeostasis of eukaryotic membrane permeability and fluidity. Both compounds have beneficial effects on human health. As the current sources of sterols and squalene are plant and shark oils, microalgae are suggested as more sustainable sources. Nonetheless, the high costs of production and processing still hinder the commercialization of algal cultivation. Strain improvement for higher product yield and tolerance to harsh environments is an attractive way to reduce costs. Being an intermediate in sterol synthesis, squalene is converted to squalene epoxide by squalene epoxidase. This step is inhibited by terbinafine, a commonly used antifungal drug. In yeasts, some terbinafine-resistant strains overproduced sterols, but similar microalgae strains have not been reported. Mutants that exhibit greater tolerance to terbinafine might accumulate increased sterols and squalene content, along with the ability to tolerate the drug and other stresses, which are beneficial for outdoor cultivation. To explore this possibility, terbinafine-resistant mutants were isolated in the model green microalga Chlamydomonas reinhardtii using UV mutagenesis. Three mutants were identified and all of them exhibited approximately 50 percent overproduction of sterols. Under terbinafine treatment, one of the mutants also accumulated around 50 percent higher levels of squalene. The higher accumulation of pigments and triacylglycerol were also observed. Along with resistance to terbinafine, this mutant also exhibited higher resistance to oxidative stress. Altogether, resistance to terbinafine can be used to screen for strains with increased levels of sterols or squalene in green microalgae without growth compromise.

Comparative Study of Chemical Compositions and Antioxidant Capacities of Oils Obtained from 15 Macadamia (Macadamia integrifolia) Cultivars in China

The planting area of macadamia in China accounted for more than one third of the world’s planted area. The lipid compositions, minor components, and antioxidant capacities of fifteen varieties of macadamia oil (MO) in China were comparatively investigated. All varieties of MO were rich in monounsaturated fatty acids, mainly including oleic acid (61.74–66.47%) and palmitoleic acid (13.22–17.63%). The main triacylglycerols of MO were first time reported, including 19.2–26.1% of triolein, 16.4–18.2% of 1-palmitoyl-2,3-dioleoyl-glycerol, and 11.9–13.7% of 1-palmitoleoyl-2-oleoyl-3-stearoyl-glycerol, etc. The polyphenol, α-tocotrienol and squalene content varied among the cultivars, while Fuji (791) contained the highest polyphenols and squalene content. Multiple linear regression analysis indicated the polyphenols and squalene content positively correlated with the antioxidant capacity. This study can provide a crucial directive for the breeding of macadamia and offer an insight into industrial application of MO in China.

Fatty Acid Profile, Lipid Quality and Squalene Content of Teff (Eragrostis teff (Zucc.) Trotter) and Amaranth (Amaranthus caudatus L.) Varieties from Ethiopia

Teff and amaranth are gluten-free cereals with significant nutritional and health benefits. However, they are underutilized and known in limited areas of the world. The present study evaluated the fatty acid profile, crude fat, squalene content and lipid quality of seven teff (Eragrostis teff (Zucc.) Trotter) and three amaranth (Amaranthus caudatus L.) varieties from Ethiopia. The fat content ranged from 2.92 to 3.34% (averaging 3.06%) and from 8.28 to 9.21% (averaging 8.6%) for teff and amaranth, respectively. Linoleic, oleic and palmitic acid were predominant in both teff and amaranth, accounting for approximately 89 and 85% of total fatty acid content, respectively. The saturated to unsaturated fatty acids ratio ranged from 0.30 to 0.32 in teff and from 0.38 to 0.40 in amaranth. The parameters used to describe lipid quality, i.e., thrombogenicity and atherogenicity indices, show that teff was superior over amaranth, suggesting a preference for the former for healthy food formulation. The squalene content of white amaranth (486.54 mg/100 g DM) was significantly higher than that of the other two varieties (327.54 and 340.81 mg/100 g DM for red and brown amaranth, respectively). In general, both gluten-free crops should be exploited for their potential as ingredients for the development of novel functional foods.

Rhodosporidium sp. DR37: a novel strain for production of squalene in optimized cultivation conditions

Background Rhodosporidium strain, a well-known oleaginous yeast, has been widely used as a platform for lipid and carotenoid production. However, the production of squalene for application in lipid-based biofuels is not reported in this strain. Here, a new strain of Rhodosporidium sp. was isolated and identified, and its potential was investigated for production of squalene under various cultivation conditions. Results In the present study, Rhodosporidium sp. DR37 was isolated from mangrove ecosystem and its potential for squalene production was assessed. When Rhodosporidium sp. DR37 was cultivated on modified YEPD medium (20 g/L glucose, 5 g/L peptone, 5 g/L YE, seawater (50% v/v), pH 7, 30 °C), 64 mg/L of squalene was produced. Also, squalene content was obtained as 13.9% of total lipid. Significantly, use of optimized medium (20 g/L sucrose, 5 g/L peptone, seawater (20% v/v), pH 7, 25 °C) allowed highest squalene accumulation (619 mg/L) and content (21.6% of total lipid) in Rhodosporidium sp. DR37. Moreover, kinetic parameters including maximum specific cell growth rate (μmax, h−1), specific lipid accumulation rate (qp, h−1), specific squalene accumulation rate (qsq, h−1) and specific sucrose consumption rate (qs, h−1) were determined in optimized medium as 0.092, 0.226, 0.036 and 0.010, respectively. Conclusions This study is the first report to employ marine oleaginous Rhodosporidium sp. DR37 for accumulation of squalene in optimized medium. These findings provide the potential of Rhodosporidium sp. DR37 for production of squalene as well as lipid and carotenoids for biofuel applications in large scale. Graphic abstract

Rhodosporidium Sp. DR37: A Novel Strain For Production of Squalene in Optimized Cultivation Conditions

Background: Rhodosporidium strain, a well-known oleaginous yeast, has been widely used as a platform for lipid and carotenoid production. However, the production of squalene for application in lipid-based biofuels is not reported in this strain. Here, we isolated and identified newly strain of Rhodosporidium sp. DR37 and investigated its potential for production of squalene under various cultivation conditions.Results: In the present study, Rhodosporidium sp. DR37 was isolated from mangrove ecosystem and its potential for squalene production was assessed. When Rhodosporidium sp. DR37 was cultivated on non-optimized medium (20 g/L glucose, 5 g/L peptone, 5 g/L YE, 15 g/L agar, seawater (50% v/v), pH 7, 30 °C), 64 mg/L of squalene was produced. Significantly, use of optimized medium (20 g/L sucrose, 5 g/L peptone, seawater (20 % v/v), pH 7, 25 °C) allowed highest squalene accumulation in Rhodosporidium sp. DR37 (619 mg/L). The maximum squalene content was obtained as 21.6% of total lipid in comparison to the non-optimized medium (13.9% of total lipid).Conclusions: This study is the first report to employ marine oleaginous Rhodosporidium sp. DR37 for accumulation of squalene in optimized medium. Our findings provide the potential of Rhodosporidium sp. DR37 for production of squalene as well as lipid and carotenoids for biofuel applications in large scale.