The bioeconomy concept was initially focused on resource substitution, aiming to mitigate the depletion of fossil resources and confer an alternative approach for resource utilization [...].
The aim of the present study was to evaluate the impact of thermal drying of immobilized Lactobacillus delbrueckii subsp. bulgaricus on apple pieces on the use of the derived biocatalyst in whey fermentation. The thermally dried immobilized biocatalyst was compared to wet and freeze-dried immobilized cells, in respect to maintenance of cell viability and fermentation efficiency. The thermal drying process appeared to be more efficient on survival rate as an 84% of the cells used for immobilization survived the process, while the freeze-drying process led to a 78% rate. The thermally dried immobilized biocatalyst was used in 12 repeated batch fermentations of synthetic lactose medium and whey at 37, 45, and 50 °C in order to evaluate its metabolic activity. The high number of repeated batch fermentations showed a tendency for high operational stability. Fermentations continued for up to 2 months without any significant loss of metabolic activity. SPME GC/MS analysis of aroma-related compounds revealed the distinctive character of fermented whey produced by the thermally dried immobilized bacterium cells. The effect of storage at 4–6 °C for up to 165 days of the biocatalyst, held directly after drying and after repeated batch fermentations, on fermentation activity was also studied. After storage, reactivation in whey was immediate, and the immobilized biocatalyst was able to produce up to 51.7 g/L lactic acid at 37 °C. The potential of thermally dried immobilized L. delbrueckii as a starter culture for food production was subsequently evaluated.
<span lang="EN-US">The bioeconomy initially focused on resource substitution, including the production of biomass from various resources; its conversion, fractionation, and processing by means of biotechnology; and chemistry and process engineering towards the production and marketing of food, feed, fuel, and fibre. Nevertheless, although resource substitution is still considered important, the emphasis has been recently shifted to the biotechnological innovation perspective of the bioeconomy, in terms that ensure environmental sustainability.</span> <span lang="EN-US">It is estimated that around one-third of the food produced for human consumption is wasted throughout the world, posing not only a sustainability problem related to food security but also a significant environmental problem. Food waste streams, mainly derived from fruits and vegetables, cereals, oilseeds, meat, dairy, and fish processing, have unavoidably attracted the interest of the scientific community as an abundant reservoir of complex carbohydrates, proteins, lipids, and functional compounds, which can be utilized as raw materials for added-value product formulations.</span> <span lang="EN-US">This Special Issue focuses on innovative and emerging food and by-products processing methods for the sustainable transition to a bioeconomy era. Contributions addressing valorisation, the bioprocessing and biorefining of food industry-based streams, the isolation of high-added-value compounds, applications of resulting bio-based chemicals to food products, novel food formulations, economic policies for food waste management, and sustainability or technoeconomic analyses of the proposed processing methods are welcome in this Special Issue.</span>
A natural resin retrieved from Pistacia terebinthus tree was evaluated as an immobilization carrier of Saccharomyces cerevisiae AXAZ-1 cells targeting successive fermentation batches of sugar synthetic mediums. Fermentation times below 54 h were recorded at temperatures 28–14 °C. In total, 147 compounds were detected using gas chromatography-mass spectrometry (GC-MS) analysis, including alcohols, esters, ketones, aldehydes, acids, and terpenes. Principal component analysis indicated that the state of cells (free/immobilized) and the fermentation temperature primarily affected terpenes’ composition. Importantly, no spoilage of the fermented beverages was noted during 90 days of storage at room temperature, most likely due to the high content of extracted terpenoids and phenols (up to 579.01 mg L−1 and 171.8 mg gallic acid equivalent L−1, respectively). Likewise, the developed novel biocatalyst (yeast cells immobilized within Pistacia terebinthus resin) was suitable for the production of low alcohol beverages with an enhanced aromatic profile. The obtained results revealed that the proposed bioprocess shows great commercialization potential in the new fast-growing low-alcohol beverages sector.
Abstract Two hundred and twenty-three olive samples of different olive cultivars (Koroneiki, Asprolia, Lianolia, Ntopia, Thiaki, Mavrolia, and Others) grown in the Ionian islands (Kefalonia, Kerkyra, Leukada, and Zakynthos) were subjected to headspace solid phase microextraction coupled to gas chromatography/mass spectrometry analysis. The aim of the study was to characterize the aroma pattern of these olive oil cultivars, and track whether specific volatile compounds could be used for olive oil cultivar authentication using chemometrics. Multivariate analysis of variance implemented on the semi-quantitative data of volatile compounds (alcohols, aldehydes, benzene derivatives, esters, hydrocarbons, ketones, and terpenoids), showed that olive cultivar had a significant impact on the volatile composition of olive oil samples. Factor analysis and linear discriminant analysis indicated those specific volatile compounds that could be related to olive oil cultivar and established statistical models for the olive oil cultivar authentication from Ionian islands, thus indicating a characteristic aroma fingerprint of these olive oils.
