Membrane filtration and isoelectric precipitation technological approaches for the preparation of novel, functional and sustainable protein isolate from lentils Abstract Isoelectric precipitation and ultrafiltration were investigated for their potential to produce protein products from lentils. Higher protein concentrations were obtained when ultrafiltration was used (> 90%), whereas isoelectric precipitation resulted in higher contents of dietary fibre and some minerals (i.e., sodium and phosphorus). Differences in the functional properties between the two ingredients were found as the isoelectric precipitated ingredient showed lower protein solubilities over the investigated pH range (from 3 to 9) which can be linked to the slightly higher hydrophobicity values (2688.7) and total sulfhydryl groups (23.9 µM/g) found in this sample. In contrast, the protein ingredient obtained by ultrafiltration was superior with regard to its solubility (48.3%; pH 7), fat-binding capacity (2.24 g/g), water holding capacity (3.96 g/g), gelling properties (11%; w/w), and foam-forming capacity (69.6%). The assessment of the environmental performance showed that both LPIs exhibited promising properties and low carbon footprints in comparison to traditional dairy proteins.

Assessment of Tunisian virgin olive oils via synchronized analysis of sterols, phenolic acids, and fatty acids in combination with multivariate chemometrics Abstract Olive oil composition and connection between effective physicochemical factors characterizing accessions from different Tunisian farming sites viz. Chemlali Sfax, Chemalali Medenine, and Zalmati Medenine, located in the centre and the south of Tunisia, was probed in this study. The relationship between olive oil composition and physicochemical characteristics from different Tunisian cultivars, namely, Chemlali Sfax, Chemlali Medenine, and Zalmati Medenine, located in the centre and the south of Tunisia, was investigated using multivariate statistical analysis. Multiple linear regressions (MLR) and artificial neural network (ANN) methodologies were employed to expose hidden relationships between oxidative stability and olive oil components such as fatty acids, phenolic acids, and sterol contents. Obtained results showed not only that the selected components are dependent on geographical location and varietal origin of olive oils, but also that fatty acids (C16:1, C17:1, C18:0, C18:1, and C18:2), specific phenols (p-hydroxyphenylacetic, o-coumaric, and gallic acids), and sterols (campestanol, stigmasterol, and sitostanol) are directly implied in the oxidative stability variation. However, ANN analysis allowed to obtain more accurate models with higher robustness (R2> 98%). The combined analytical approaches, MLR and ANNs, could be considered as an adequate experimental model to restrain the influence of olive oil components in characterization of olive oil quality. Here, we have addressed the aim of using different analytical instruments in this field and the application of chemometrics for sterols, phenolic acids, and fatty acid analysis.

LC–QQQ and LC–QTOF MS methods for comprehensive detection of potential allergens in various propolis extracts Abstract Propolis is a highly complex matrix, in which phenolics are the mostly analyzed constituents. However, detailed propolis analysis is often lacking due to the high price of the commercially available phenolic standards and the lack of standards of phenols that are causing allergic reaction to propolis. Therefore, it is crucial to develop methods for detection and quantification of these constituents so that, afterwards, propolis extractions can be adjusted to the desired final application. Developed mass spectrometry-based methods were used for the quantification of 25 known phenols as well as for the identification and quantification of 27 additional phenolic derivatives, for which the standards are not readily available. We demonstrated that these newly discovered phenolic derivatives may have a high share in propolis, among which hydroxycinnamic are the most important ones as they are responsible for allergenic properties of propolis-based products. To track the changes in hydroxycinnamic acid derivatives, different propolis extract were prepared and analyzed with developed protocol. All obtained data were processed using chemometric tools to gain insight into allergens content in different propolis extracts. The presented protocol is in line with the food and pharma industry’s growing needs for a comprehensive knowledge on the propolis composition, as it is used in a variety of functional and medicinal products. Knowing that some phenolic components may exert unwanted side effects, a precise selection of a fraction of compounds from propolis is essential for the development of safe-end products.

Rapid screening of olive oil cultivar differentiation based on selected physicochemical parameters, pigment content and fatty acid composition using advanced chemometrics Abstract Thirty-seven olive oil samples belonging to cultivars: Ntopia, Koroneiki, Thiaki, Asprolia and Lianolia were collected from four Western Greek islands. Samples were subjected to the following physicochemical analyses: acidity, peroxide value, K232, K270, ΔK indices, chlorophyll and carotenoid contents, along with fatty acids in an effort to characterize and mainly classify olive oil samples according to cultivar. Multivariate analysis of variance (MANOVA) showed that the following parameters: acidity, chlorophyll, carotenoid, myristic acid, margaric acid, stearic acid, arachidic acid, and eicosenoic acid were significant (p < 0.05) for the classification of olive oil cultivars. The aforementioned parameters were subjected to linear discriminant analysis (LDA) providing a correct classification rate of 91.9% and 81.1% using the original and cross-validation methods, respectively. Finally, the application of quality control analysis such as Pareto chart showed that with only two variables namely acidity and chlorophyll content, the investigated cultivars could be differentiated, providing thus, a rapid and costless methodology for olive oil cultivar differentiation.

Antioxidant capacities and polyphenols in autumn-growing cultivar of Chinese cabbage ( Brassica rapa L. ssp. pekinensis cv. Bulam Plus) Abstract The effects of drought stress in autumn-growing Chinese cabbage cultivar on bioactive compounds, total antioxidant and binding properties to human serum albumin (HSA) were studied. Seedlings of 42 days growing Chinese cabbage Brassica rapa L. ssp. pekinensis cv. Bulam Plus (BRARP) were transplanted and maintained into pots during 3 weeks with soil water of the drought-treated (D-T) and control (C) plants at 10% and 30%, respectively. Polyphenols and the values of antioxidant capacities by three radical scavenging assays (CUPRAC, FRAP, ABTS) were determined in methanol extracts of the samples. MS spectra of phenolic extracts were compared in samples treated at different periods of time. The total polyphenols and their activities were slightly lower in drought-treated Chinese cabbage than in corresponding controls. The influence of polyphenols, total antioxidant and binding activities in D-T plants accumulation at drought stress in Chinese cabbage BRARP was reduced. Our study provides valuable information that Chinese cabbage BRARP can be consumed throughout the year in South Korea and other countries.

Effects of flour mean particle size, size distribution and water content on rheological properties of wheat flour doughs Abstract This investigation is focused on the granulometric and rheological analysis of two kinds of wheat flour, i.e. type 0 and type 00. The granulometric analysis was carried out using a laser diffraction particle size analyzer. The particle size distribution of the type 0 and 00 flours, expressed as the mass median diameter (D(v,0.5)), was 80.922 µm and 71.686 µm, respectively. The rheological characterization of physical mixtures of wheat flour and water was carried out by means of small deformation dynamic oscillatory measurements. The rheological measurements evidenced a different behavior of the two samples of flour when they were mixed with water. Namely, the progressive addition of water to the type 0 wheat flour favored a decrease of G′ and G″ values, emphasizing that the dough becomes less full-bodied, while its structure remains unmodified; in fact, the phase-angle was not influenced by the water content. On the contrary, the type 00 wheat flour mixed with increased water content provided a dough characterized by lower elastic and viscous moduli, even though the behavior of the phase angle progressively varied. The different results may be due to the different particle size distribution of the flour and the different percentage of gluten present in each. Thanks to this parallel study of the particle size distribution of flours and the rheological behavior of the derived doughs, new food preparation procedures and new research on adulteration in the bread production can be designed.

Foaming, emulsifying and rheological properties of extracts from a co-product of the Quorn fermentation process Abstract This study assessed the functional profile (foaming, emulsifying and rheological properties), proteomic and metabolomic composition of a naturally foaming and currently unexploited co-product (centrate) from the Quorn fermentation process. Due to the low environmental footprint of this process the centrate is a potential source of sustainable functional ingredients for the food industry. A range of fractions were isolated from the centrate via successive ultrafiltration steps. The retentate 100 (R100) fraction, which was obtained following a 100 kDa ultrafiltration, displayed good foaming, emulsifying and rheological properties. R100 solutions and oil-in-water emulsions displayed high viscosity, while R100 solutions and hydrogels showed high viscoelasticity. R100 foams displayed high stability while oil-in-water R100 emulsions showed small and stable oil droplet size distributions. Large mycelial aggregates were reported in R100 solutions and gels, correlating with their high viscosity and viscoelasticity. A dense mycelial network was observed in R100 foams and contributing to their stability. In parallel tensiometry measurements highlighted the presence of interfacially active molecules in R100 which formed a rigid film stabilising the oil/water interface. A number of functional metabolites and proteins were identified in the centrate, including a cerato-platanin protein, cell membrane constituents (phospholipids, sterols, glycosphingolipids, sphingomyelins), cell wall constituents (chitin, chitosan, proteins), guanine and guanine-based nucleosides and nucleotides. This study highlighted the potential of functional extracts from the Quorn fermentation process as novel ingredients for the preparation of sustainable food products and the complex and specific nature of the centrate’s functional profile, with contributions reported for both mycelial structures and interfacially active molecules. Graphical abstract

The effects of germanium and selenium on growth, metalloid accumulation and ergosterol content in mushrooms: experimental study in Pleurotus ostreatus and Ganoderma lucidum Abstract The aim of this study was to examine the effects of substrate supplementation with germanium (Ge) and selenium (Se), alone or combined, on the growth, element accumulation and ergosterol content in the fruiting bodies of the mushroom species Ganoderma lucidum and Pleurotus ostreatus. Both species were grown in four independent experimental systems with different concentrations of germanium powder (1, 5 and 10 mM), selenite [Se(IV)] and selenate [Se(VI)] (0.1, 0.4 and 0.8 mM of each Se species). Se supplementation caused no observable changes to morphology while the addition of Ge induced changes in size and/or colour, especially for P. ostreatus. A synergistic effect of Ge supplementation on Se accumulation in fruiting bodies of G. lucidum was observed only at the two highest levels of supplementation with both elements. Even though inorganic Se was used to enrich the experimental substrates, organic Se compounds dominated in the fruiting bodies. Increasing levels of Ge in the substrates elevated the content of organic selenium in the fruiting bodies of G. lucidum. No such trend was recorded in P. ostreatus. The maximum mean Ge levels in P. ostreatus and G. lucidum reached up to 70 and 80 mg kg−1, respectively. However, the bioaccessibility of this element was low, in the range 5.4–6.6% (P. ostreatus) and 0.4–7.6% (G. lucidum). Ergosterol content in the fruiting bodies of both species displayed the highest values in all the experimental systems supplemented with Se. The addition of Ge and Se + Ge resulted in losses of ergosterol content in comparison to cultivation with Se supplementation and control. The obtained results show the significant role of Ge–Se interaction in the accumulation of these elements in the studied mushroom species.

Nutritional aspects and botanical origin recognition of Mediterranean honeys based on the “mineral imprint’’ with the application of supervised and non-supervised statistical techniques Abstract The nutritional aspects and the potential of aluminum (Al), calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), antimony (Sb), silicon (Si) and zinc (Zn) for the botanical origin recognition of 270 citrus, fir, multifloral, pine and thyme honeys from Greece, Cyprus, Egypt, Spain, and Morocco were investigated. The aforementioned minerals were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). Quantitative data were subjected to supervised and non-supervised statistical techniques such as multivariate analysis of variance (MANOVA), linear discriminant analysis (LDA), k-nearest neighbors (k-NN) and multiple correspondence analysis (MCA), to estimate whether minerals could effectively assist in the botanical origin recognition of Mediterranean honeys. Results showed that Mediterranean honeys had nutritional properties on the basis of the daily mineral intake contribution that was estimated, whereas Mg, Cu, Mn, Al, Ca, and Si could imply potential markers of Mediterranean honeydew and nectar honey botanical origin. The work carried out may comprise the tool for the accurate labeling of honey from different countries protecting consumers from fraud and set the basis for a cooperative organization, in the near future, dealing with the market distribution of a nutritious and authentic Mediterranean honey (AMH).

Key aroma compounds in fermented Forastero cocoa beans and changes induced by roasting Abstract The influence of the roasting procedure on the composition of key aroma compounds in fermented Forastero cocoa beans was investigated. For this purpose, the volatile fractions from the unroasted, fermented and the roasted cocoa were isolated by extraction/SAFE distillation, and the odour-active constituents were characterised by gas chromatography–olfactometry in combination with an aroma extract dilution analysis. A total of 41 aroma compounds in the flavour dilution (FD) factor range of 2–8192 were identified in the unroasted and 42 compounds with FD factors of 2–8192 in the roasted cocoa beans. Qualitatively, the set of aroma compounds was nearly identical in both samples; however, differences in the flavour dilution factors were observed. 2- and 3-Methyl butanoic acid (sweaty) and acetic acid (vinegar-like, sour) showed the highest FD factors in the unroasted beans, while 3-methylbutanal (malty), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (caramel-like) and 2- and 3-methyl butanoic acid (sweaty) were detectable by GC/O in the highest dilutions in the roasted seeds. Quantitation of the most odour-active compounds by means of stable isotope dilution assays, followed by calculation of odour activity values (OAV, ratio of concentration to odour threshold), revealed concentrations above the threshold level for 20 compounds in the unroasted and 24 compounds in the roasted beans. The roasting procedure led to a strong increase, in particular, in the concentrations of the two Strecker aldehydes 3-methylbutanal (malty) and phenylacetaldehyde (honey-like) as well as 4-hydroxy-2,5-dimethyl-3(2H)-furanone (caramel-like).