Aikaterini Georgala

Effect of draining temperature on the biochemical characteristics of Feta cheese

Two different draining temperatures, 15 and 21°C were applied to five Feta cheese curds made with different starters, containing mesophilic or thermophilic strains or mixtures of them. After 20 h of draining, the pH of curds made with thermophilic starters ranged from 5.28 to 5.49. The draining temperature significantly affected (P<0.05) the pH and the total solids of the cheeses. The inclusion of whey proteins in the cheese curd due to the insufficient draining of cheeses at 15°C, resulted in higher water-soluble nitrogen (WSN), as % of total nitrogen content. Free amino acid contents were significantly affected (P<0.05) by the draining temperature and by the presence of thermophilic lactobacilli in the starter mixture. Draining temperature also significantly affected (P<0.05) residual αs- and β-casein and the RP-HPLC profiles of the WSN. The C2:0 to C8:0 free fatty acids, hardness (kg) and fracturability (kg), as well as the total organoleptic scores, were significantly (P<0.05) higher in feta drained at 21°C.

Mycelial fatty acid composition of Pleurotus spp. and its application in the intrageneric differentiation

The mycelial fatty acid profiles of several Pleurotus strains and their application in intrageneric differentiation were investigated. In the lipids produced by strains of Pleurotus abalonus, P. calyptratus, P. columbinus, P. cornucopiae, P. cystidiosus, P. ostreatus, P. pulmonarius, P. sajor-caju and P. sapidus , the predominant fatty acid was linoleic (33–68% total lipids), while in P. eryngii strains the major fatty acid was oleic (43–46%). In all strains studied, oleic and palmitic acids were present in significant concentrations (> 12%), whereas stearic acid was found in lower ones. By using the ratios C18:1/C18:0, C18:2/C18:1 and C18/C16:0 as variables, Pleurotus strains were clustered into six groups. Group I ( P. ostreatus ); group II, divided in three sub-groups (IIa: P. columbinus , IIb: P. eryngii , IIc: P. cornucopiae ), group III, divided in two sub-groups (IIIa: P. sajor-caju , IIIb: P. pulmonarius ), group IV ( P. sapidus ), group V ( P. abalonus ) and group VI divided in two sub-groups (VIa: P. cystidiosus and VIb: P. calyptratus ). It is concluded that the mycelial fatty acid composition of Pleurotus can be used in the intrageneric taxonomy of the genus.

Volatile compounds and lipolysis levels of Kopanisti, a traditional Greek raw milk cheese

BACKGROUND Kopanisti is a Protected Designation of Origin (PDO) traditional soft Greek cheese manufactured exclusively in the Cycladic island complex. It is made from raw bovine, ovine or caprine milk or a mixture of them without the addition of any lactic acid cultures. It has a spreadable texture, an intense salty and peppery taste and a strong flavour. Although Kopanisti cheese has properties similar to those of mould-ripened cheeses, its volatile compound content has never been reported. In this study the volatile compound content and lipolysis level of ten commercial Kopanisti samples were investigated. RESULTS The main aromatic groups found in Kopanisti cheese were alcohols, esters and volatile free fatty acids. Ethanol and several ethyl esters were the main volatile compounds. Intense lipolysis was present, with an average total free fatty acid content of 48,979 mg kg(-1). Acetic, butyric and capric acids were the main volatile acids determined. CONCLUSION The intense lipolysis contributes greatly to the strong flavour and peppery taste of Kopanisti cheese. The flavour of Kopanisti is attributable mainly to the volatile fatty acids and various other volatile compounds as well as to the interactions occurring between them.

The Nutritional Value of Two Fermented Milk/Cereal Foods Named âÂÂGreek rahanasâ and âÂÂTurkish Tarhanaâ : A Review

Fermented foods are an important part of diets in many parts of the world and are known from ancient times. Traditional fermented cereal foods are widely used in the diet of people in the Middle East, Asia, Africa and some parts of Europe. The technology of making these products as well as the type of milk and cereal used are of the main factors that influence their nutritional value. Nutritional and safety benefits have been attributed to fermented foods which are an important part of people diets. ‘Trahanas’ in Cyprus and Greece and ‘Tarhana’ in Turkey are two of the oldest traditional fermented milk/cereal foods and very nutritive foods due to the nutritional properties of wheat and milk/yoghurt. This work is a review on the nutritional value of these products.