Camelina (Camelina sativa (L.) Crantz) oilcake – untapped resource of phenolic compounds

The work includes a comprehensive study of phenolic compounds, their occurrence and identification in the residues after pressing of the oil from camelina seeds of Slovenian origin, i.e. oilcake. In addition, the efficiencies of antioxidant determinations using different methods according to different mechanisms are presented. These data demonstrate that almost all of the phenolic compounds in these seeds remain in the seed oilcake. The following antioxidants were confirmed: sinapine, 4-vinylphenol, 4-vinylguaiacol, 4-vinylsyringol, 4-vinylcatechol, ellagic acid, protocatechuic acid, <em>p</em>-hydroxybenzoic acid, sinapic acid, salicylic acid, catechin, quercetin and quercetin glucoside. The oilcake has high reducing power and radical scavenging activity. Heat treatment of seeds affects the amount of free, soluble and insoluble bound phenolic compounds as well as antioxidant capacity of individual fractions. Potential applications of camelina oilcake in the food industry are further justified by comparisons with other oilcakes and synthetic antioxidant

Development and optimisation of solid-phase extraction of extractable and bound phenolic acids in spelt (Triticum spelta L.) seeds

A solid-phase extraction (SPE) technique was developed and optimised for isolation and concentration of extractable and bound phenolic acids from germinated spelt seeds, for analysis by liquid chromatography–mass spectrometry. Samples initially underwent solvent extraction under different conditions to maximise the yield of phenolic antioxidants. Optimal extraction conditions for extractable phenolics were absolute methanol as solvent, sample-to-methanol ratio 1:9, and reconstitution in non-acidified water. The bound phenolics were extracted from sample pellets using hydrolysis with 2 M NaOH, acidification of the hydrolysate with formic acid, and simultaneous isolation and purification using Strata X polymeric RP tubes. Compared to liquid-liquid extraction, this direct SPE protocol has significant advantages in terms of higher extraction efficiencies of total and individual phenolics and their antioxidant activities. These data suggest that direct SPE represents a rapid and reliable method for quantitative analysis of both the extractable and the commonly overlooked bound phenolics in Triticum spelta seeds

Simulated Gastrointestinal Digestion of Bioprocessed Spelt Seeds: Bioaccessibility and Bioactivity of Phenolics

The goal of this research was to evaluate the impact of different bioprocessing techniques on improved bioaccessibility of phenolics from spelt seeds. Despite the negative influence of gastrointestinal digestion, fermentation of germinated seeds significantly increased the bioaccessibility of total phenolics and their antioxidant activity compared to digested raw seeds. Enzymatic treated fermented seeds showed the highest relative bioaccessibility of p-coumaric and trans-ferulic acids, while their absolute contents were significantly higher in &ldquo;germinated + fermented&rdquo; seeds. Our research suggests that pretreatment of spelt seeds with hydrolytic enzymes improves access of fermenting microorganisms to structural elements, resulting in an increased content of extractable and bound trans-ferulic acid. Significantly higher biostability of phenolics was observed in raw seeds. Some major quality changes in the composition of extracts were observed under simulated in vitro digestion, since antioxidants of the same extract showed a different relative decrease in DPPH&bull; and ABTS&bull;+ scavenging activities compared to the raw seeds or their corresponding undigested counterparts. It is therefore important to increase the content of extractable antioxidants in seeds by bioprocessing, since they are strongly diminished during digestion

Enzymatic treatments of raw, germinated and fermented spelt (Triticum spelta L.) seeds improve the accessibility and antioxidant activity of their phenolics

Our study aimed to investigate the effect of cellulase, xylanase, esterase, α-amylase and protease on the enhanced release of phenolics from spelt seeds, and to demonstrate the co-effect of enzymatic treatment, germination or fermentation on the spelt phenolics content and their in vitro and cellular antioxidant activities. Bound phenolics of spelt seeds were successfully released by different combinations of cellulase, xylanase, feruloyl esterase, α-amylase and protease. Samples treated with all five enzymes together showed significantly improved extractable p-coumaric, ferulic and p-hydroxybenzoic acid contents, particularly efficient antioxidant activity in ABTS$^{•+}$ scavenging activity and the highest extractable TPCs. By combining enzymatic treatment with germination and fermentation, extractable TPCs were increased by 28% and 458%, respectively. A combination of enzymatic treatment with germination and fermentation led to enormously increased extractable trans-ferulic acid content (5899% and 8263%, respectively). The bound fraction of enzymatic treated raw seeds showed lower decrease in intracellular oxidation than the corresponding extractable fraction, but a 24-fold higher uptake of hydroxycinnamic acids. Principal component analysis showed some similarities between extractable and bound fractions of enzymatic treated raw, germinated and fermented samples, mainly due to the increase in extractable acids content (biochemical parameters), especially cis-ferulic, caffeic and p-hydroxybenzoic acids

Bioprocessed Wholegrain Spelt Flour Improves the Quality and Physicochemical Characteristics of Wheat Bread

In the present study, the partial substitution of common white wheat flour for a bread recipe with variously bioprocessed wholegrain spelt was investigated. The addition of 1% and pasteurised 5% “germinated + enzymatic treated” spelt flour to wheat flour significantly improved the specific volume of the bread, but their texture profile analysis and sensory evaluation were not satisfactory. A higher percentage of added bioprocessed spelt flour darkened the colour of the bread. Breads with the addition of more than 5% of bioprocessed spelt flour were unacceptable in terms of quality and sensory parameters. The highest extractable and bound individual phenolics were found in breads with 5% “germinated + fermented” spelt flour (GFB5) and 5% pasteurised “germinated + enzymatic treated” spelt flour (GEB5P). A strong positive correlation was determined between trans-ferulic acid and TPC and DPPH• radical scavenging activity. The GEB5P bread showed the highest increase in extractable and bound trans-ferulic acid content, by 320% and 137%, respectively, compared to the control bread. Principal component analysis showed differences between the control bread and enriched breads in terms of their quality, sensory and nutritional properties. Breads with 2.5% and 5% “germinated + fermented” spelt flour had the most acceptable rheological, technological and sensory characteristics, in addition to a substantial improvement in their antioxidant content

Changes in the Bioaccessibility of Antioxidants after Simulated In Vitro Digestion of Bioprocessed Spelt-Enhanced Wheat Bread

The aim of the study was to determine whether the partial replacement of wheat flour with bioprocessed spelt flour contributes to a higher bioaccessibility of the antioxidants in bread. The results showed that the type and amount of bioprocessed spelt flour in a bread recipe has a major impact on the extractable and bound TPC, the content of individual phenolics, their antioxidant activity, and their bioaccessibility as determined by in vitro digestion. Extractable p-coumaric and trans-ferulic acids in breads decreased after digestion, while extractable cis-ferulic and p-hydroxybenzoic acids increased. The bioaccessibility of TPC in the control bread (100% wheat flour), and in bread enriched with 5% “germinated + fermented” spelt flour (GFB5), did not differ. However, the digested GFB5 bread contained 5.2-times more extractable, and 1.3-times more bound, trans-ferulic acid than the digested control bread. trans-Ferulic acid showed the lowest bioaccessibility, up to 2.8%. In GFB2.5 and GFB5 breads, the bioaccessibility of p-coumaric, trans-ferulic, and cis-ferulic acids was higher than in other digested breads. PCA visualized the difference between the undigested and digested breads. The incorporation of germinated and fermented, or germinated and enzymatic, treated spelt flour in a white bread recipe could be an attractive way of providing consumers with nutritionally interesting foods

Antioxidant and antimicrobial activity of extracts obtained from rosemary (Rosmarinus officinalis) and vine (Vitis vinifera) leaves

The antioxidant properties and antimicrobial activity of rosemary extracts were compared to those of vine leaf extracts. The phenolics were quantified by HPLC. Rosemary extracts were stronger in reducing power than vine leaf extracts but possessed weaker superoxide anion radical (O2•−) scavenging capability. The antimicrobial activity was confirmed by the broth microdilution test using minimal inhibitory (MIC) concentrations against gram-positive (Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes) and gram-negative bacteria (Campylobacter jejuni, Salmonella Infantis, Escherichia coli O157:H7). The kinetics of survival was assessed using the broth macrodilution method. The study confirmed the stronger antibacterial activity of rosemary extracts, especially against gram-positive bacteria and C. jejuni. The antioxidant and antimicrobial activity of vine leaf extracts did not correlate with their contents of flavan-3-ols and flavonols. For rosemary extracts the absence of a correlation between their activities and the content of carnosic acid suggests that protective efficiency is achieved through interactions among phenolic constituents