Evolution of proteolysis during the ripening of traditional Feta cheese

Abstract

-Four cheesemaking trials were conducted in three different traditional Feta cheese plants. The characteristics of the cheesemaking process had to do with: the heat treatment of the cheese milk, the use of yoghourt as a starter, the use of traditional rennet from kids' and lambs' abomasa, and the packaging in wooden barrels without brine addition. At 60 d (minimum ripening period according to Greek Codex Alimentarius), the percentage of water soluble nitrogen (WSN) varied from 15.88% to 19.58% of total nitrogen (TN) and 73.4%-79.9% of the WSN was nitrogen soluble in 12% TCA. At the same age, 13.3-23.6% of WSN was nitrogen soluble in 5% PTA. The quantitative and qualitative changes of the middle area of the RP-HPLC profiles (A 220 ) indicated the evolution of nitrogenous fractions during the ripening and the effect of each cheese plant technology on them. Most of the qualitative and quantitative changes occured during the pre-ripening period (18 d). In general, the rate of proteolysis was similar to that of the industrially made Feta. However, the percentages of low molecular weight fractions were higher. Feta cheese / proteolysisRésumé -Évolution de la protéolyse au cours de l'affinage de fromage Feta fabriqué par les fromageries traditionnelles. Quatre fabrications expérimentales de fromage Feta ont été réalisées dans trois différentes fromageries traditionnelles. La technologie adoptée par ces fromageries se caracté-rise par : une pasteurisation en cuve, l'utilisation de yaourt comme levain, l'emprésurage par la pré-sure traditionnelle obtenue à partir de caillettes d'agneaux ou de chevreaux ainsi que l'emballage et le stockage dans des barils en bois sans ajout de saumure complémentaire. de l'affinage ainsi que l'effet de la technologie des différentes fromageries. La plus grande partie des changements qualitatifs et quantitatifs a été observée pendant les 18 premiers jours d'affinage. La vitesse de la protéolyse a été égale à celle de fromage Feta fabriqué industriellement. Cependant les valeurs des fractions azotées de faible poids moléculaire étaient plus élevées.Feta / fromage / protéolyse

Contribution of rennet and starter to proteolysis in Iranian UF white cheese

“…In our study, the lack of notable degradation of caseins in rennet-free cheeses confirms this hypothesis. Similar observations were reported by Moatsou et al [33] for Feta cheese. Primary proteolysis of caseins in cheese is generally due mainly to the activity of chymosin (on α s1 -casein) and of plasmin (on β-casein) [17] but they are not the sole active proteolytic agents [29].…”

Effects of packaging materials on some ripening characteristics of Tulum cheese

“…The greatest part of the water-soluble nitrogen (>64 %) is consisted of nitrogen that is soluble in 12 % trichloroacetic acid (TCA), which corresponds to medium and small-sized (600-15.000 Dalton molecular mass) peptides with 2-22 amino acids (Moatsou et al, 2002;Roseiro et al, 2003). It was reported that rennet, bacterial proteinases and peptidases are responsible for the formation of some 12 % trichloroacetic acid-soluble nitrogen (TCA-SN) .…”

“…TCA-SN ratios of plastic cheeses were higher than skin cheeses followed by pot, cloth and stomach cheeses, respectively (Table 1) As proteolysis continues in cheese, relatively larger molecular weight nitrogenous fractions brought about by chymosin and cell-wall proteinases are further degraded to smaller molecular weight compounds by peptidases. The formation of amino acids and peptides with molecular weight less than 600 Dalton, which are soluble in 5 % phosphotungstic acid (PTA), is strongly related to the age and flavour intensity of cheese (Moatsou et al, 2002). The phosphotungstic acid-soluble nitrogen (PTA-SN) values, which occur as a result of peptidolysis are commonly used to determine the type and the extent of proteolysis (Moatsou et al, 2002;Roseiro et al, 2003).…”

“…The formation of amino acids and peptides with molecular weight less than 600 Dalton, which are soluble in 5 % phosphotungstic acid (PTA), is strongly related to the age and flavour intensity of cheese (Moatsou et al, 2002). The phosphotungstic acid-soluble nitrogen (PTA-SN) values, which occur as a result of peptidolysis are commonly used to determine the type and the extent of proteolysis (Moatsou et al, 2002;Roseiro et al, 2003). It was observed that plastic packaged Tulum cheeses had the highest PTA-SN while the Tulum cheeses ripened in stomach packaging materials had the lowest PTA-SN (Table 1) and no significant differences were found for the PTA-SN contents (p>0.05) of the cheeses.…”

Research of lipolytic processes in functional products made from raw materials of the Carpathian region

“…В результаті катаболізму аміно-кислот утворюються такі леткі сполуки, як леткі жирні кислоти, альдегіди, спирти, сульфонільні компоненти, складні ефіри та інші сполуки [20][21][22]. Вільні аміно-кислоти та їх похідні є основними компонентами смако-ароматичної композиції сирів.…”