Orange processing waste valorisation for the production of bio-based pigments using the fungal strains Monascus purpureus and Penicillium purpurogenum

Orange processing wastes have been evaluated for the production of pigments by the fungal strains Monascus purpureus ATCC 16365 and Penicillium purpurogenum CBS 113139. Solid state fermentations were initially conducted on waste orange peels with the fungal strain M. purpureus aiming to assess various pigment extraction methods, the effect of particle size as well as the effect of nitrogen addition and incubation time. Under the optimum conditions, solid state fermentations were also performed with the strain P. purpuronegum to evaluate pigment production on waste orange peels. M. purpureus was more efficient than P. purpurogenum for the production of pigments during solid state fermentation, yielding 9 absorbance units (AU) per g of dry fermented substrate. Semi-solid state fermentations were subsequently conducted by suspending waste orange peels in liquid media leading to pigment production of up to 0.95 AU mL−1. Submerged fermentations were carried out with both fungal strains using aqueous extracts from either boiled or hydrodistilled orange peel residues as the sole fermentation medium showing that up to 0.58 AU mL−1 of pigment production could be achieved. Each fermentation feedstock and fermentation mode influenced significantly the production of pigments by each fungal strain used

Production of Food Grade Yeasts

Kvasci su poznati čovjeku vec tisućama godina jer se koriste u tradicionalnim fermentacijskim procesima dobivanja vina, piva i kruha. Danas se oni koriste i kao alternativni izvori visokovrijednih proteina, enzima i vitamina, imaju brojnu primjenu u proizvodnji zdravstveno korisne hrane kao aditivi, regulatori i sastojci arome, u proizvodnji mikrobioloških podloga i ekstrakata, te kao krmivo. Suvremena znanstvena dostignuća omogućuju izolaciju, izradu i industrijsku proizvodnju novih sojeva kvasaca koji ispunjavaju posebne zahtjeve prehrambene industrije. U radu su istaknuti tipovi industrijskih prehrambenih kvasaca, procesi njihove proizvodnje i sirovine. Također se raspravlja o metabolizmu kvasca, s obzirom na utrošak ugljikohidrata, hranjiva te nova dostignuća u njihovu istraživanju.Yeasts have been known to humans for thousands of years as they have been used in traditional fermentation processes like wine, beer and bread making. Today, yeasts are also used as alternative sources of high nutritional value proteins, enzymes and vitamins, and have numerous applications in the health food industry as food additives, conditioners and flavouring agents, for the production of microbiology media and extracts, as well as livestock feeds. Modern scientific advances allow the isolation, construction and industrial production of new yeast strains to satisfy the specific demands of the food industry. Types of commercial food grade yeasts, industrial production processes and raw materials are highlighted. Aspects of yeast metabolism, with respect to carbohydrate utilization, nutritional aspects and recent research advances are also discussed