Vincenza Ferraro

Extraction of high added value biological compounds from sardine, sardine-type fish and mackerel canning residues--a review.

Different valuable compounds, which can be employed in medicine or in other industries (i.e. food, agrochemical, pharmaceutical) can be recovered from by-products and waste from the fish canning industries. They include lipids, proteins, bio-polymers, minerals, amino acids and enzymes; they can be extracted from wastewaters and/or from solid residues (head, viscera, skin, tails and flesh) generated along the canning process, through the filleting, cooking, salting or smoking stages. In this review, the opportunities for the extraction and the valorisation of bioactive compounds from sardine, sardine-type fish and mackerel canning residues are examined and discussed. These are amongst the most consumed fishes in the Mediterranean area; moreover, canning is one of the most important and common methods of preservation. The large quantities of by-products generated have great potentials for the extraction of biologically desirable high added value compounds.

Cassava (Manihot esculenta Crantz) and Yam (Dioscorea spp.) Crops and Their Derived Foodstuffs: Safety, Security and Nutritional Value

Cassava (Manihot esculenta Crantz) and yam (Dioscorea spp.) are tropical crops consumed by ca. 2 billion people and represent the main source of carbohydrate and energy for the approximately 700 million people living in the tropical and sub-tropical areas. They are a guarantee of food security for developing countries. The production of these crops and the transformation into food-derived commodities is increasing, it represents a profitable business and farmers generate substantial income from their market. However, there are some important concerns related to the food safety and food security. The high post-harvest losses, mainly for yam, the contamination by endogenous toxic compounds, mainly for cassava, and the contamination by external agents (such as micotoxins, pesticides, and heavy metal) represent a depletion of economic value and income. The loss in the raw crops or the impossibility to market the derived foodstuffs, due to incompliance with food regulations, can seriously limit all yam tubers and the cassava roots processors, from farmers to household, from small-medium to large enterprises. One of the greatest challenges to overcome those concerns is the transformation of traditional or indigenous processing methods into modern industrial operations, from the crop storage to the adequate package of each derived foodstuff.

Evaluation of the interactions between rosmarinic acid and bovine milk casein

Polyphenols can interact with proteins, which gives rise to a significant loss of their biological properties. The objective of this research was the study of interactions in model systems composed of the polyphenol rosmarinic acid (RA) and bovine milk α-s1-casein, β-casein and κ-casein. Radical cation quenching assay (ABTS, 2,2′-azinobis-3-ethyl-benzothiazoline-6-sulfonic-acid), optical density, liquid chromatography (RP-HPLC, reverse phase-high performance liquid chromatography, and SEC, size exclusion chromatography), dynamic light scattering (DLS) and zeta-potential, Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were used for the screening of the interactions at 0, 3 and 24 h of storage time and at the refrigeration temperature 4 °C. Interactions were assessed at the pH of the complexes in water, 6.8, and at acidic pH 3 and 4.5. Results showed the occurrence of non-covalent interactions such as hydrophobic, hydrogen bonding and dipole–dipole. Radical cation quenching activity of RA significantly decreased in the presence of caseins, meaning that the amount of free RA diminished. Higher and the same degree of interaction were observed for α-s1-casein and β-casein. Complex dimensions were different depending on pH, time and on the primary and secondary structure of caseins. Interactions were shown to be favoured at the lowest pH, where complexes are biggest, and reversible at all pH conditions tested. The results of this study must be complemented with the analysis of more complex systems to take into account the effect of other milk components – lipids, sugars and minerals – on the interaction of RA.

Collagen type I from bovine bone. Effect of animal age, bone anatomy and drying methodology on extraction yield, self-assembly, thermal behaviour and electrokinetic potential

Natural collagen is easily available from animal tissues such as bones. Main limitations reported in the use of natural collagen are heterogeneity and loss of integrity during recovery. However, its natural complexity, functionality and bioactivity still remain to be achieved through synthetic and recombinant ways. Variability of physicochemical properties of collagen extracted from bovine bone by acetic acid was then investigated taking into account endogenous and exogenous factors. Endogenous: bovines bones age (4 and 7 years) and anatomy (femur and tibia); exogenous: thermal treatments (spray-drying and lyophilisation). Scanning electron microscopy, spectroscopy (EDS, FTIR, UV/Vis and CD), differential scanning calorimetry (DSC), centesimal composition, mass spectrometry, amino acids and zeta-potential analysis were used for the purpose. Age correlated negatively with yield of recovery and positively with minerals and proteoglycans content. Comparing the anatomy, higher yields were found for tibias, and higher stability of tibias collagen in solution was noticed. Whatever the age and the anatomy, collagens were able to renature and to self-assemble into tri-dimensional structures. Nonetheless thermal stability and kinetics of renaturation were different. Variability of natural collagen with bone age and anatomy, and drying methodology, may be a crucial advantage to conceive tailor-made applications in either the biological or technical sector.

Screening and molecular identification of lactic acid bacteria from gari and fufu and gari effluents

Bacterial strains were isolated from cassava-derived food products and, for the first time, from cassava by-products, with a focus on gari, a flour-like product, and the effluents from the production processes for gari and fufu (a dough also made from cassava flour). A total of 47 strains were isolated, all of which were tested to determine their resistance to acidic pH and to bile salt environments. Four of the 47 isolates tested positive in both environments, and these four isolates also showed antibacterial behaviour towards both Gram-positive and Gram-negative microbial pathogens (i.e. Methicillin-resistance Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Salmonella enteritidis, Escherichia coli, Escherichia coli (O157), Yersinia enterocolitica). In most cases, the antibacterial activity was related to bacteriocin production. Molecular identification analysis (16S rDNA and randomly amplified polymorphic DNA-PCR) revealed that the four isolates were different strains of the same species, Lactobacillus fermentum. These results demonstrate that bacteria isolated from cassava-derived food items and cassava by-products have interesting properties and could potentially be used as probiotics.