Pre-treatment and extraction techniques for recovery of added value compounds from wastes throughout the agri-food chain

The enormous quantity of food wastes discarded annually force to look for alternatives for this interesting feedstock. Thus, food bio-waste valorisation is one of the imperatives of the nowadays society. This review is the most comprehensive overview of currently existing technologies and processes in this field. It tackles classical and innovative physical, physico-chemical and chemical methods of food waste pre-treatment and extraction for recovery of added value compounds and detection by modern technologies and are an outcome of the COST Action EUBIS, TD1203 Food Waste Valorisation for Sustainable Chemicals, Materials and Fuels

Lycopene recovery from tomato peel under mild conditions assisted by enzymatic pre-treatment and non-ionic surfactants

The tomato processing industry generates large quantities of tomato peel residues, usually creating environmental problems. These residues are a significant source of lycopene, thus providing an attractive alternative for profitable handling of these otherwise problematic byproducts. The enzymatic pretreatment of these residues for lycopene recovery has already been employed, although the use of surfactants for enhancing the recovery has not been examined so far. The enzymatic pretreatment of tomato peels, using two commercially available pectinolytic enzyme preparations, was evaluated suggesting that there is an optimum pretreatment time of about 1 h, enzyme amount 250 Units/mL and no significant pH influence. Lycopene surfactant - assisted extraction was further investigated, showing that, among eight surfactants used, the most suitable was "Span 20", with an optimum ratio of 6-7 surfactant molecules per lycopene molecule. Sequential enzymatic pretreatment and surfactant-assisted extraction (30 min for each step) was evaluated leading to an improved lycopene extraction yield, with a somewhat smaller surfactant molar ratio (i.e. 4-5). In the latter case, the yield of lycopene recovery was almost four times greater compared to just 1 hr enzymatic pretreatment, and was approximately ten times greater compared to the recovery from untreated peels. Furthermore, such lipophilic compound recovery, avoiding the use of organic solvents, is environmentally attractive and ensures direct lycopene use in the food and cosmetics industries

Agro-food wastes utilization by Blakeslea trispora for carotenoids production

The all-trans-β-carotene is a natural pigment used in various industrial fields (food, cosmetics, pharmaceuticals, etc) and possesses the higher provitamin A activity, in respect to other carotenoids. All-trans-β-carotene is produced industrially by chemical and biotechnological means. For β-carotene biotechnological production in industrial scale mated cultures of Blakeslea trispora, a heterothallic fungus, are mainly used. Despite the intense research for β-carotene production by B. trispora, natural substrate utilization has not been extensively studied. Solid agro-food wastes such as cabbage, watermelon husk and peach peels from northern Greece as main carbon source into submerged B. trispora cultures for carotenoids production, was examined. The media containing only the agro-food waste (2-4) gave a biomass accumulation 7.77±0.4 g/L, while a reference medium 1 with glucose (10 g/L) gave 4.65±0.21 g/L. In another experiments series agro-food wastes were used with corn steep liquor and thiamine (media 6-8), giving a biomass accumulation and total carotenoid volumetric production 10.2±2.41 g/L and 230.49±22.97 mg/L, respectively. These are the higher values reported for solid wastes so far in respect to those obtained from a synthetic medium, with higher glucose concentration of 50 g/L where the correspondent values were 9.41±1.18 g/L and 45.63 mg/L respectively. The results support that B. trispora is able to utilize, almost equivalently, different origin agrofood wastes for carotenoids production. Furthermore, β-carotene percentage in all examined cases was over 76%, as it was estimated by HPLC analysis, suggesting that these agro food wastes may be used for high purity, large scale β carotene production

Encapsulation of the peptide Ac-Glu-Thr-Lys-Thr-Tyr-Phe-Trp-Lys-NH 2 into polyvinyl alcohol biodegradable formulations:effect of calcium alginate

It has been recently reported that the peptide Ac-Glu-Thr-Lys-Thr-Tyr-Phe- Trp-Lys-NH2, analogue of the Glu1811-Lys1818 region of A3 light chain of blood coagulation factor VIII, presents in vitro significant anticoagulant activity. The encapsulation of this peptide into different polyvinyl alcohol formulations is examined here. The formulations were prepared using polyvinyl alcohol cross-linked with either boric acid or glutaraldehyde, giving a series of twelve different hydrogels. In case of PVA-boric acid method, a small percentage of sodium alginate was used in order to avoid bead's agglomeration. In that case, the most efficient encapsulation of the octapeptide (74%) was achieved with 0.2% (w/w) sodium alginate. It was also observed that the increase in sodium alginate percentage leads to beads with increased peptide release time, ranging from 60 to 90 min at 0.02% and 1% (w/w) sodium alginate respectively. The water holding of the PVA gels was estimated to be 27% regardless of the cross-linking reagent used, while it was increased with increasing sodium alginate concentration and reached about 60% for 1% sodium alginate. The longer octapeptide release, at 120 min, was observed with PVA-glutaraldehyde hydrogel, with encapsulation efficiency comparable to those obtained with boric acid, indicating that this hydrogel may be further used in drug delivery systems

Natural origin lycopene and its “green” downstream processing

Lycopene is an abundant natural carotenoid pigment with several biological functions (well-known for its antioxidant properties) which is under intensive investigation in recent years. Lycopene chemistry, its natural distribution, bioavailability, biological significance, and toxicological effects are briefly outlined in the first part of this review. The second, major part, deals with various modern downstream processing techniques, which are assessed in order to identify promising approaches for the recovery of lycopene and of similar lipophilic compounds. Natural lycopene is synthesized in plants and by microorganisms, with main representatives of these two categories (for industrial production) tomato and its by-products and the fungus Blakeslea trispora, respectively. Currently, there is a great deal of effort to develop efficient downstream processing for large scale production of natural-origin lycopene, with trends strongly indicating the necessity for “green” and mild extraction conditions. In this review, emphasis is placed on final product safety and ecofriendly processing, which are expected to totally dominate in the field of natural-origin lycopene extraction and purification

Substrate contribution on free radical scavenging capacity of carotenoid extracts produced from Blakeslea trispora cultures

Blakeslea trispora produces carotenoids mixtures consisting mainly of lycopene, γ-carotene and β-carotene, together with trace amounts of other carotenoid precursors. The yield of these carotenoids and their composition are greatly affected by culture substrate. The scavenging capacity of carotenoids extract from cultures of B. trispora growing in various substrates was estimated using the 2,2-diphenyl-1-picrylhydrazyl method. Fractions enriched in β-carotene, γ-carotene and lycopene, obtained after column chromatography in alumina basic II, were also examined. Substrates containing starch and oils mixture, Ni2+, and that with pantothenic acid presented higher antioxidant activity. An increase in the antioxidant activity of the crude carotenoid extract compared to that of the isolated fractions enriched in β-carotene, γ-carotene and lycopene respectively, observed in most samples, indicated a possible synergistic effect. The results are of interest and by expanding this study to more substrates and other microorganisms- producing antioxidants, a formulation of extract with high free radical scavenging potential could be produced

Long-term performance of a membrane bioreactor treating table olive processing wastewater

BACKGROUND: Table olive processing wastewater (TOPW) is a seriously polluting and difficult to treat effluent, characterized by widely fluctuating pH and salinity, as well as high concentrations of organic matter and polyphenols. This systematic long-term study in a laboratory-scale pilot demonstrates that membrane bioreactor (MBR) technology is effective in substantially bio-degrading TOPW. RESULTS: After implementation of an appropriate protocol of active biomass acclimatization/proliferation, the MBR pilot was operated for 6 months with real TOPW effluent, under various operating conditions. Total organic carbon (TOC) and total polyphenol (TPh) compounds removal efficiencies were very high with mean values 91.5 and 82.8%, respectively; nutrient (N and P) removal was also satisfactory. The membrane exhibited stable performance at moderate biomass concentration, with a tendency to deteriorate at higher biomass concentration. Fouled membrane permeability could be fully restored by implementing the usual chemical cleaning protocols. CONCLUSIONS: Despite the high percentage TOC and TPh removal, the MBR effluent requires final post-treatment to remove a yellowish tint and further reduce its organic content, depending on local discharge standards. The MBR can serve as the basic treatment process in an integrated scheme for TOPW management, which needs additional R&D to further develop and optimize