Natural <i>β</i>-Carotene Production by <i>Blakeslea trispora</i> Cultivated in Spanish-Style Green Olive Processing Wastewaters

In the current research, the potential of Spanish-style green olive processing wastewaters (lye and washing waters) exploitation toward natural β-carotene production by Blakeslea trispora was tested for the first time. Mating culture generated by the joint cultivation of the heterothallic fungal strains ATCC 14271 and 14272 in the non-sterile lye and washing waters was able to grow, achieving the phytotoxic hydroxytyrosol degradation by 57.3% and 66.8%, respectively. However, the low sugar and nitrogen content of the streams did not favor carotenogenesis. Alternatively, in the nutrient-enriched effluents, a notable quantity of β-carotene was produced, accounted for 61.2 mg/L (lye) and 64.1 mg/L (washing waters) (82–88% of total carotenoid content). Above all, enriched streams had a noteworthy stimulating effect on the β-carotene synthesis, because both the maximum β-carotene yield per volume of enriched effluents and specific β-carotene production rate were higher when compared with the respective values obtained from trials with synthetic reference medium without added effluents. Hydroxytyrosol and tyrosol showed high stability during the non-sterile process for β-carotene production by B. trispora grown in the enriched effluents. This finding strengthens the potential toward the generation of multiple high-value products, which could lower the natural β-carotene production costs

Natural β-Carotene Production by Blakeslea trispora Cultivated in Spanish-Style Green Olive Processing Wastewaters

In the current research, the potential of Spanish-style green olive processing wastewaters (lye and washing waters) exploitation toward natural β-carotene production by Blakeslea trispora was tested for the first time. Mating culture generated by the joint cultivation of the heterothallic fungal strains ATCC 14271 and 14272 in the non-sterile lye and washing waters was able to grow, achieving the phytotoxic hydroxytyrosol degradation by 57.3% and 66.8%, respectively. However, the low sugar and nitrogen content of the streams did not favor carotenogenesis. Alternatively, in the nutrient-enriched effluents, a notable quantity of β-carotene was produced, accounted for 61.2 mg/L (lye) and 64.1 mg/L (washing waters) (82–88% of total carotenoid content). Above all, enriched streams had a noteworthy stimulating effect on the β-carotene synthesis, because both the maximum β-carotene yield per volume of enriched effluents and specific β-carotene production rate were higher when compared with the respective values obtained from trials with synthetic reference medium without added effluents. Hydroxytyrosol and tyrosol showed high stability during the non-sterile process for β-carotene production by B. trispora grown in the enriched effluents. This finding strengthens the potential toward the generation of multiple high-value products, which could lower the natural β-carotene production costs

On the Role of the Carboxyl Group to the Protective Effect of o-dihydroxybenzoic Acids to Saccharomyces cerevisiae Cells upon Induced Oxidative Stress

In the present work, the role of the carboxyl group of o-dihydroxybenzoic acids (pyrocatechuic, 2,3-diOH-BA and protocatechuic, 3,4-diOH-BA) on the protection against induced oxidative stress in Saccharomyces cerevisiae was examined. Catechol (3,4-diOH-B) was included for comparison. Cell survival, antioxidant enzyme activities, and TBARS level were used to evaluate the efficiency upon the stress induced by H2O2 or cumene hydroperoxide. Theoretical calculation of atomic charge values, dipole moment, and a set of indices relevant to the redox properties of the compounds was also carried out in the liquid phase (water). Irrespective of the oxidant used, 2,3-diOH-BA required by far the lowest concentration (3&ndash;5 &mu;M) to facilitate cell survival. The two acids did not activate catalase but reduced superoxide dismutase activity (3,4-diOH-BA&gt;2,3-diOH-BA). TBARS assay showed an antioxidant effect only when H2O2 was used; equal activity for the two acids and inferior to that of 3,4-diOH B. Overall, theoretical and experimental findings suggest that the 2,3-diOH-BA high activity should be governed by metal chelation. In the case of 3,4-diOH BA, radical scavenging increases, and chelation capacity decreases. The lack of carboxyl moiety (3,4-diOH B) improves to radical scavenging, interaction with lipophilic free radicals, and antioxidant enzymes. The present study adds to our knowledge of the antioxidant mechanism of dietary phenols in biological systems

Processing Wastewaters from Spanish-Style cv. Chalkidiki Green Olives: A Potential Source of Enterococcus casseliflavus and Hydroxytyrosol

The purpose of this study was to examine the isolation of indigenous lactic acid bacteria (LAB) with functional properties from Spanish-style cv. Chalkidiki green olive processing wastewaters (GOW). Predominant indigenous LAB could serve as bioaugmentation agents/starter culture for table olives production and protected designation of origin specification. Spontaneous fermentation of fresh GOW over different temperatures (15 °C to 50 °C) and pH values (3.5 to 11.5) for 30 d enabled the isolation/molecular identification of the lactic acid bacterium Enterococcus casseliflavus and the plant-associated bacterium Bacillus amyloliquefaciens subsp. plantarum. E. casseliflavus was found to reduce chemical oxygen demand by 72%. Its resistance to extreme pH values, salinity, and temperature was successfully modeled and the minimum inhibitory concentration of oleuropein against the bacterial growth was determined (0.9 g/L). Furthermore, hydroxytyrosol content was doubled (up to 553 mg/L) after GOW spontaneous fermentation under acidic conditions at 15 °C to 30 °C for 120 d, creating an additional source of input. These results highlight the significance and potential of E. casseliflavus in Spanish-style cv. Chalkidiki green olive processing

Changes in Phenolic Compounds and Phytotoxicity of the Spanish-Style Green Olive Processing Wastewaters by Aspergillus niger B60

This study systematically investigated the degradation kinetics and changes in the composition of phenolic compounds in Spanish-style Chalkidiki green olive processing wastewaters (TOPWs) during treatment using Aspergillus niger B60. The fungal growth and phenol degradation kinetics were described sufficiently by the Logistic and Edward models, respectively. The maximum specific growth rate (2.626 1/d) and the maximum degradation rate (0.690 1/h) were observed at 1500 mg/L of total polar phenols, indicating the applicability of the process in TOPWs with a high concentration of phenolic compounds. Hydroxytyrosol and the other simple phenols were depleted after 3–8 days. The newly formed secoiridoid derivatives identified by HPLC-DAD-FLD and LC-MS are likely produced by oleoside and oleuropein aglycon via the action of fungal β-glucosidase and esterase. The treated streams were found to be less phytotoxic with reduced chemical oxygen demand by up to 76%. Findings will provide useful information for the subsequent treatment of residual contaminants

Bay Laurel (Laurus nobilis L.) Essential Oil as a Food Preservative Source: Chemistry, Quality Control, Activity Assessment, and Applications to Olive Industry Products

Essential oils (EOs) find application as flavoring agents in the food industry and are also desirable ingredients as they possess preservative properties. The Mediterranean diet involves the use of a lot of herbs and spices and their products (infusions, EOs) as condiments and for the preservation of foods. Application of EOs has the advantage of homogeneous dispersion in comparison with dry leaf use in small pieces or powder. Among them, Laurus nobilis (bay laurel) L. EO is an interesting source of volatiles, such as 1,8-cineole and eugenol, which are known for their preservative properties. Its flavor suits cooked red meat, poultry, and fish, as well as vegetarian dishes, according to Mediterranean recipes. The review is focused on its chemistry, quality control aspects, and recent trends in methods of analysis and activity assessment with a focus on potential antioxidant activity and applications to olive industry products. Findings indicate that this EO is not extensively studied in comparison with those from other Mediterranean plants, such as oregano EO. More work is needed to establish authenticity and activity methods, whereas the interest for using it for the preparation of flavored olive oil or for the aromatization and preservation of table oils must be further encouraged

Bioeconomy and the production of novel food products from agro-industrial wastes and residues under the context of food neophobia

Advances in bioeconomy lead to exploitation of wastes for the production of high added-value products. Sometimes, these products face consumer resistance due to a phenomenon known as "neophobia." The aim of this study was the investigation of consumer acceptance/rejection of a novel food product and the segmentation of consumers according to their "food neophobia tendency." A "functional" novel yogurt derived from halloumi whey was chosen as a hypothetical scenario. Data was collected through a survey in typical urban areas in Greece and Cyprus. Statistical analysis revealed three types of "food neophobia tendency" in each study area. Regarding the acceptability of the novel yogurt, consumers are driven by their curiosity about the taste of the novel yogurt, while the main factor of rejection was found in the absence of a health issue.Paraskevi Tsimitri and Anastasios Michailidis (Aristotle University of Thessaloniki, Greece), Efstratios Loizou (Institute of Soil Science and Plant Cultivation - State Research, Institute (IUNG-PIB), Poland, Technological Education Institute of Western Macedonia, Greece), Fani Th Mantzouridou (Aristotle University of Thessaloniki, Greece), Konstantinos Gkatzionis (University of Birmingham, UK, University of the Aegean, Greece), Ediriisa Mugampoza (Kyambogo University)Includes bibliographical reference

Exploring the Potential of Halloumi Second Cheese Whey for the Production of Lactic Acid Cultures for the Dairy Industry

Production of halloumi cheese in Cyprus has increased rapidly over the last decade since the popularity of the cheese is growing. This results in excess production of whey streams that pose serious environmental concerns and are difficult to manage. In our study, the poorly investigated second cheese whey (SCW) generated after the extraction of anari, a by-product of halloumi cheese manufacture, was examined for dairy industry lactic acid bacteria (LAB) culture production. The LAB studied were all initially isolated from SCW. These LAB were molecularly identified and characterized in an attempt to explore their potential use as starter cultures for the dairy industry. A total of 11 Gram-positive and catalase-negative isolates were identified, belonging to four different species/subspecies: Lactobacillus delbrueckii subsp. lactis, Lactobacillus delbrueckii subsp. jakobsenii, Lactobacillus leichmannii and Lactobacillus crispatus. Lactose/galactose utilization tests demonstrated species-specific differences in galactose and lactose catabolism. Interestingly, culturing the selected isolates in SCW supplemented with skimmed milk (30% total solids) improved their freeze-drying tolerance (75–91% survival rate depending on the species). Moreover, isolates in vacuum-packed powders maintained viability and metabolic activity over 3-month storage at 4 °C

Novel Foods and Neophobia: Evidence from Greece, Cyprus, and Uganda

The exploitation of agri-food industrial by-products to produce novel foods is a promising strategy in the framework of policies promoting the bioeconomy and circular economy. Within this context, this study aims to examine the effect of food neophobia and food technology neophobia in the acceptance of a novel food by consumers (through an EU research project: Sybawhey). As a case study, a functional yogurt-like product was developed by synergistic processing of halloumi cheese whey, enriched with banana by-products. The present study contributes to the literature by examining consumers’ perceptions for such a novel food, identifying the profile of potential final users and classifying them according to their “neophobic tendency”. A comparative approach among groups from Greece, Cyprus and Uganda was adopted to explore whether respondents have a different attitude towards this novel yogurt. Results suggest that there is a potential for increasing consumption of novel foods derived by agri-food industrial by-products, but more information about the importance of using by-products are required to enhance consumers’ acceptance of this novel food. Such results may be useful to policy makers, aiming to promote strategies towards the effective reuse of food outputs leading to the manufacture of sustainable novel foods