Maria Alexandri

Ionian University | IONIO · Department of Food Science and Technology

This study investigated the integrated valorization of defatted rice bran (DRB) by converting it into lactic acid (LA) and subsequently utilizing the residues from LA production for biomethane generation through anaerobic digestion (AD). Processing 480 kg of DRB resulted in the production of 70 L of pure LA and generated significant waste streams,...

Polysaccharides and protein–polysaccharide complexes produced from the fungal strain Trametes versicolor have demonstrated bioactive properties that depend on the substrate, the fermentation conditions and also the fungal strain. Likewise, the submerged and controlled fermentation of medicinal mushrooms elicits numerous advantages over traditional...

In this study, whey protein edible films with improved hydrophobic and antioxidant properties were developed through the addition of oil-based components deriving from spent coffee grounds (SCG). Initially, the recovery of the oil fraction from SCG was performed using conventional and “green” extraction techniques. Results showed that a higher reco...

Numerous compounds obtained from the medicinal mushroom Ganoderma lucidum have evidenced renowned bioactive characteristics. Controlled fermentation to generate fungal mycelia confers several advantages, specifically when the valorization of agro-industrial streams as fermentation feedstocks is included. Submerged fermentation of a newly isolated G...

New types of sourdough breads are proposed, made with freeze-dried sourdough adjuncts based on: (i) Lactiplantibacillus plantarum subsp. plantarum ATCC 14917, a potential probiotic (LP) alone or (ii) with the addition of unfermented pomegranate juice (LPPO) and (iii) pomegranate juice fermented by the same strain (POLP). Physicochemical, microbiolo...

Biotechnologically produced carotenoids occupy an important place in the scientific research. Owing to their role as natural pigments and their high antioxidant properties, microbial carotenoids have been proposed as alternatives to their synthetic counterparts. To this end, many studies are focusing on their efficient and sustainable production fr...

Increased awareness of environmental concerns and innovative green technologies have paved the way towards the development of biological conversion routes and sustainable processes to produce bio-based platform chemicals, biopolymers, bioenergy and materials employing green manufacturing. Research has focused on the valorization of agricultural and...

Purpose The growth behavior of novel fungal isolates along with the production of bioactive compounds from mycelia mass during submerged fermentations were investigated using conventional synthetic media and agro-industrial residues as fermentation substrates. Methods Four novel isolated fungi, belonging to edible or medicinal species, were evalua...

The development of microbial cell factories is nowadays a main route for the production of safe and environmentally friendly bioactive compounds. Rhodosporidium kratochvilovae yeasts constitute an unexplored source for the production of natural carotenoids, thus further insights on their metabolism and fermentative behavior would contribute towards...

Research on biosurfactants (BS) is consistently increasing in the past years, driven from their beneficial attributes over chemical surfactants. Lactobacilli (LAB) and yeast BS producers could prevail over the pathogenic strains, owing to their GRAS status, to broaden end-applications toward the food and pharmaceutical industries. However, the incr...

The addition of natural components with functional properties in novel food formulations confers one of the main challenges that the modern food industry is called to face. New EU directives and the global turn to circular economy models are also pressing the agro-industrial sector to adopt cradle-to-cradle approaches for their by-products and wast...

The development of innovative functional products with potential health benefits, under the concept of bio-economy, is flourishing. This study undertook an evaluation of non-dairy lactobacilli Lactiplantibacillus pentosus B329 and Lactiplantibacillus plantarum 820 as “ready to use” starter cultures. Lactic acid bacteria (LAB) cultures were evaluate...

This study presents the production of D-lactic acid with high enantiomeric purity using lignocellulosic hydrolysates from newly isolated lactic acid bacterial (LAB) strains. Six strains, 4 heterofermentative and 2 homofermentative, were investigated for their ability to grow and produce lactic acid on sugar beet pulp (SBP) hydrolysates, containing...

Valorisation of food supply chain waste for the production of bio-based platform chemicals will facilitate the transition to the sustainable bio-economy era. To this end, a novel process has been developed for the conversion of grape pomace and stalks into bio-based succinic acid. Free sugars (2.55 g/100 g), a phenolic-rich extract (185.75 mg galli...

An integrated biorefinery has been developed using winery wastes (grape pomace-GP, stalks-GS, wine lees-WL). Bacterial cellulose was produced from GP extracted free sugars. Grape-seed oil and polyphenols were extracted from GP. Experimental design was employed to optimize lignin removal (50.8%) from mixtures of remaining GP solids and GS via NaOH (...

Millions of tons of fresh fruit are produced each year which are being processed to products such as juice and canned fruit. As a result, a large amount of solid and liquid waste is produced during fruit processing that have to be appropriately managed. Management and disposal patterns include landfilling, their application as soil improvement addi...

The formation of either acetoin or D-2,3-butanediol (D-BDO) by Bacillus amyloliquefaciens cultivated on bakery waste hydrolysates has been evaluated in bioreactor cultures by varying the volumetric oxygen transfer coefficient (kLa). The highest D-BDO production (55.2 g L⁻¹) was attained in batch fermentations with kLa value of 64 h⁻¹. Batch ferment...

The biotechnological production of platform chemicals from renewable resources is in the scientific spotlight, as researchers seek to develop environmentally friendly and cost-efficient processes to compete with the petroleum-based ones. Lactic acid (LA) is an established platform chemical, registering an important market share, mainly owing to the...

The utilisation of waste materials and industrial residues became a priority within the bioeconomy concept and the production of biobased chemicals. The aim of this study was to evaluate the feasibility to continuously produce L-lactic acid from different renewable substrates, in a multi-substrate strategy mode. Based on batch experiments observati...

The numerous environmental problems caused by the extensive use of fossil resources have led to the formation of the circular bioeconomy concept. Renewable resources will constitute the cornerstone of this new, sustainable model, with biomass presenting a huge potential for the production of fuels and chemicals. In this context, waste and by-produc...

In integrated biorefineries, physical and mechanical, thermochemical, chemical as well as biotechnological processes are applied in order to simultaneously obtain various products belonging to the classes: Food, feed, materials, chemicals, and energy, from various biogenic feedstocks. The focus on the production of more than one product is also exp...

The or­ganic frac­tion of mu­nic­i­pal solid waste (OFMSW) is an abun­dant biowaste with great po­ten­tial in the bioe­con­omy model. Pre­vi­ous re­ports have demon­strated that OFMSW hy­drolysates are good sub­strates for lac­tic acid (LA) pro­duc­tion. How­ever, LA can ex­ist in two enan­tiomeric forms (L- and D-) and most com­mer­cial LA ap­pli­...

The production of biodegradable polymers as alternatives to petroleum-based plastics has gained significant attention in the past years. To this end, polylactic acid (PLA) constitutes a promising alternative, finding various applications from food packaging to pharmaceuticals. Recent studies have shown that D-lactic acid plays a vital role in the p...

Sweet sorghum juice (SSJ) was evaluated as fermentation substrate for the production of l-lactic acid. A thermophilic Bacillus coagulans isolate was selected for batch fermentations without the use of additional nutrients. The first batch of SSJ (Batch A) resulted on higher lactic acid concentration, yield and productivity with values of 78.75 g∙L−...

The numerous applications of lactic acid have made it one of the most important platform chemicals and, for many years, its biotechnological production has been the topic of intensive research. Currently, most of the lactic acid is manufactured in batch mode; however, continuous mode could offer various advantages, especially in terms of productivi...

Lactic acid is an important chemical as starting chiral material in various applications. It has increased value in the global market. Different studies have presented the possibility to obtain rich lactic acid solutions with high isomeric purity (S-form) from second-generation (2G) feedstocks. The used downstream process is crucial, not only in te...

The side streams derived from the palm oil production process, namely palm kernel cake, palm pressed fibre, palm kernel shells and empty fruit bunches, were evaluated as sources of phenolic compounds. Among these streams, kernel cake had the highest total phenolic content (in mg of gallic acid equivalents (GAE) per g of dry sample) with a value of...

Sustainable chemical production should rely on the valorisation of crude renewable resources. Waste biomass refining complies with bio-economy and circular economy initiatives. In this regard, sugar beet pulp (SBP) was efficiently fractionated into pectins, phenolic compounds and a sugar-rich hydrolysate that was subsequently used as fermentation f...

Defatted rice bran (DRB) constitutes an abundant by‐product stream, generated during rice milling and subsequent bran oil extraction. Enzymatic hydrolysis of starch and protein content in DRB was optimised in terms of solid loading. Among the four solid loadings evaluated (10%, 15%, 20% and 25%), the hydrolysate derived from 20% solids resulted in...

The microbial production of fumaric acid by Rhizopus arrhizus NRRL 2582 has been evaluated using soybean cake from biodiesel production processes and very high polarity (VHP) sugar from sugarcane mills. Soybean cake was converted into a nutrient-rich hydrolysate via a two-stage bioprocess involving crude enzyme production via solid state fermentati...

Lactic acid (LA) was produced on a pilot scale using a defined medium with glucose, acid whey, sugar bread and crust bread. The fermentation broths were then subjected to micro-and nanofiltration. Microfiltration efficiently separated the microbial cells. The highest average permeate flow flux was achieved for the defined medium (263.3 L/m 2 /h) an...

Spent sulphite liquor produced as side stream from sulphite pulping of Eucalyptus globulus hardwood could be used for the separation of lignosulphonates by nanofiltration in the retentate stream and succinic acid production via fermentation of the permeate stream by Actinobacillus succinogenes or Basfia succiniciproducens. The potential integration...

The recovery of residual oil from palm kernel cake by supercritical carbon dioxide (CO2) and compressed liquefied petroleum gas (LPG) was evaluated. Extractions were carried out in order to investigate how pressure and temperature affect the extraction yield, chemical composition and antioxidant activity of the product. Even though the maximum yiel...

The replacement of the fossil resources historically employed for chemicals’ production is of major scientific interest the last decades, as a result of the environmental issues arisen and the price versatility of petroleum. Biotechnological routes present promising alternatives for the production of various platform chemicals such as succinic, lac...

This work is focused on the optimization of the ultrasound-assisted extraction of antioxidant compounds with photoprotective effect from palm pressed fiber. The influence of ultrasound intensity and pulse cycle was investigated by means of a central composite rotational design. The optimized condition was ultrasound intensity of 120 W.cm⁻² and puls...

Spent sulphite liquor (SSL) was used as carbon source for the production of succinic acid using immobilized cultures of Actinobacillus succinogenes and Basfia succiniciproducens on two different supports, delignified cellulosic material (DCM) and alginate beads. Fed-batch immobilized cultures with A. succinogenes in alginates resulted in higher sug...

Spent sulphite liquor (SSL), the by-product stream of the acidic sulphite pulping process, contains fermentable sugars (derived from hemicellulose degradation) and various phenolic compounds. The effective removal of the phenolic compounds could result in a value-added product and at the same time this process could lead to a detoxified medium, sui...

Succinic acid production from the monosaccharides xylose, arabinose, glucose, mannose and galactose was studied using the bacterium Actinobacillus succinogenes. In Duran bottle cultures, containing 10 g/L of each of sugar, succinic acid was produced from all sugars except for galactose. The highest succinate yield, 0.56 g/g, was obtained with gluco...

Compressed liquefied petroleum gas (LPG) and CO2 were used for the extraction of bioactive compounds from palm pressed fiber (Elaeis guineensis). The influence of temperature and pressure on extraction yield, chemical composition, antioxidant activities towards superoxide and hydroxyl radicals and the sun protection factor were studied for each sol...

Spent sulphite liquor (SSL) has been used for the production of lignosulphonates (LS), antioxidants and bio-based succinic acid. Solvent extraction of SSL with isopropanol led to the separation of approximately 80% of the total LS content, whereas the fermentations carried out using the pretreated SSL with isopropanol led to the production of aroun...

The sulphite pulping process for cellulose extraction consists of lignin depolymerisation of wood by sulphonation and hydrolysis leading to the production of spent sulphite liquor (SSL) as waste stream enriched in hemicellulose sugars and lignin derivatives. In this work, liquid–liquid extraction was used in order to separate phenolics from the sug...

Spent sulphite liquor (SSL) is a by-product stream generated by the pulp and paper industry employing the sulfite pulping process. SSL contains high quantities of lignosulphonates and various C5 and C6 monosaccharides. The monosaccharides contained in SSL should be utilized for the production of value-added chemicals preferably before the separatio...