Osmotic Concentration of Gooseberry Fruits – The Infl uence of Temperature, Time and Pretreatment Methods on Mass Transfer and Total Polyphenol and Organic Acid Content

Svrha je ovoga rada bila utvrditi utjecaj temperature, vremena tretiranja i predobrade enzimima na osmotsko sušenje plodova ogrozda (kultivar Biały Triumf). Plodovi su ogrozda sušeni tijekom 5 do 240 min u otopini šećera (65 °Brix), pri temperaturi od 40 do 70 °C. Primijenjena su dva postupka: u prvom su plodovi ogrozda prije sušenja uronjeni u otopinu lipolitičkih enzima, a zatim u otopinu pektinolitičkih enzima. U drugom su postupku pektinolitički enzimi dodani otopini šećera. Kinetika je osmotskog sušenja određena praćenjem udjela suhe tvari, gubitka vlage i povećanja mase suhe tvari plodova. Vrijednosti su navedenih parametara bile veće pri višoj temperaturi i duljem vremenu obrade. Nakon jednog sata sušenja na 40 °C udjel je suhe tvari bio 13,9 %, a pri 70 °C iznosio je 20,4 %. Postupak je bio učinkovitiji kad su tijekom osmotskog sušenja dodani pektinolitički enzimi. Nakon dva sata sušenja uz obradu pektinolitičkim enzimima udjel se suhe tvari sedmerostruko povećao u usporedbi s kontrolnim uzorkom. Predobrada je lipazom i pektinazom također povećala udjel suhe tvari (do 12 puta nakon dva sata sušenja na 40 °C). Što je temperatura procesa bila niža, to su udjeli fenolnih spojeva u voću bili veći. Najveći je udjel fenolnih spojeva zadržan na 40 °C (92,2 % nakon 2 h sušenja). Ispitan je udjel organskih kiselina (jabučne, šikiminske i limunske kiseline), te je utvrđeno da je nakon jednog sata sušenja udjel limunske kiseline u voćnom sirupu bio najveći, i to od 95,9 do 83,1 %, u usporedbi s početnim uzorkom.The objective of the study is to assess the infl uence of temperature, time and enzymatic pretreatment on the osmotic concentration of gooseberry fruits (cultivar Biały Triumf). The fruits were osmotically concentrated in a sucrose solution at 65 °Brix and 40 to 70 °C for 5 to 240 min. Two experimental procedures were employed. In the fi rst procedure, prior to concentration the fruits were immersed in the solution containing lipolytic enzymes, and then in the solution containing pectinolytic enzymes. In the second procedure, pectinolytic enzymes were added to the sucrose solution. The kinetics of the osmotic concentration was studied based on the changes in dry matter content, water loss, and solid gain. Higher temperature and longer process time led to higher values of the mentioned parameters. After 1 h of concentration at 40 °C, dry matter content was 13.9 %, while at 70°C it was 20.4 %. The use of pectinolytic enzymes during osmotic concentration resulted in higher eff ectiveness of the process. After 2 h of concentration with the use of pectinolytic enzymes, solid gain was seven times higher than that in the control sample. Enzymatic treatment with lipase and pectinase before concentration also increased solid gain during osmotic concentration (up to twelve times after 2 h at 40 °C). The lower processing temperature, the higher retention of phenolic compounds in fruits was observed. The retention of phenolics was the highest at 40 °C (92.2 % at 2 h). Among organic acids (malic, shikimic and citric), the highest retention was exhibited by citric acid; at 1 h of concentration, its fraction in the obtained fruit syrup content was from 95.9 to 83.1 % as compared to the starting material

Sinteza galaktozil derivata glukonske kiseline transglikozilacijom pomoću β-galaktozidaze

Bionic acids are bioactive compounds demonstrating numerous interesting properties. They are widely produced by chemical or enzymatic oxidation of disaccharides. This paper focuses on the galactosyl derivative of gluconic acid as a result of a new method of bionic acid synthesis which utilises the transglycosylation properties of β-galactosidase and introduces lactose as a substrate. Products obtained in such a process are characterised by different structures (and, potentially, properties) than those resulting from traditional oxidation of disaccharides. The aim of this study is to determine the effect of selected parameters (concentration and ratio of substrates, dose of the enzyme, time, pH, presence of salts) on the course of the reaction carried out with the enzymatic preparation Lactozym, containing β-galactosidase from Kluyveromyces lactis. Research has shown that increased dry matter content in the baseline solution (up to 50 %, by mass per volume) and an addition of NaCl contribute to higher yield. On the other hand, reduced content of the derivative is a result of increased pH from 7.0 to 9.0 and an addition of magnesium and manganese salts. Moreover, exceeding the β-galactosidase dose over approx. 35 000 U per 100 g of lactose also leads to reduced yield of the process. The most favourable molar ratio of sodium gluconate to lactose is 2.225:0.675. Depending on the conditions of the synthesis, the product concentration ranged between 17.3 and 118.3 g/L of the reaction mixture, which corresponded to the mass fraction of 6.64–23.7 % of dry matter. The data obtained as a result of the present study may be useful for designing an industrial process.Bioničke kiseline su bioaktivni spojevi koji imaju niz zanimljivih svojstava. Najčešće se dobivaju kemijskom ili enzimskom oksidacijom disaharida. U ovom je radu ispitan galaktozil derivat glukonske kiseline, dobiven novom metodom sinteze bioničkih kiselina transglikozilacijom pomoću β-galaktozidaze uz laktozu kao supstrat. Proizvodi dobiveni ovom metodom imaju drukčiju strukturu (a time vjerojatno i svojstva) od onih dobivenih tradicionalnom oksidacijom disaharida. Svrha je ovoga rada bila odrediti utjecaj odabranih parametara (koncentracije i omjera supstrata, količine enzima, vremena, pH-vrijednosti i prisutnosti soli) na tijek reakcije katalizirane enzimskim pripravkom Lactozym, što sadržava β galaktozidazu iz kvasca Kluyveromyces lactis. Istraživanje je pokazalo da se s povećanjem udjela suhe tvari u osnovnoj otopini (do 50 % mase po volumenu) i dodatkom soli povećao prinos proizvoda. S druge strane, s povećanjem pH-vrijednosti sa 7,0 na 9,0 i dodatkom magnezijeve i manganove soli smanjio se udjel derivata. Osim toga, s povećanjem doze β-galaktozidaze na više od 35 000 jedinica u 100 g laktoze također se smanjio prinos proizvoda. Najpovoljniji molarni omjer natrijevog glukonata i laktoze bio je 2,225:0,675. Ovisno o uvjetima sinteze, koncentracija proizvoda u reakcijskoj smjesi bila je između 17,3 i 118,3 g/L, što odgovara masenom udjelu suhe tvari od 6,64 do 23,7 %. Rezultati dobiveni u ovom radu mogu poslužiti za dizajn industrijskog procesa

Mass transport and changes in the saccharide profile during osmotic dehydration of apricot and chokeberry fruits

The aim of the study was to determine the effect of osmotic dehydration in sucrose solution on the level and profile of the main saccharides in frozen chokeberry and apricot. A 50°Bx sucrose solution at a temperature of 25, 35, 45 and 55°C was used in the tests. The influence of temperature and dehydration time on the dry matter content in the tested fruits was demonstrated. Both in apricot and chokeberry the highest increase was recorded in the first hour of the process, for apricots to the level of 25.1-32.4%, for chokeberry 30.4-33.4%. The use of the highest temperature (55°C) increased the content of glucose and fructose while reducing the amount of sucrose (hydrolysis); at 25-35°C the opposite effect was obtained. At low temperatures, chokeberry was not very susceptible to migration of sucrose. Also, the transport of water was not intense. There was no correlation between the temperature of the process and the increase in dry matter in the sample. The greatest loss of water, i.e. 1 g H2O/g i.d.m., occurred after five hours at 55°C. Under analogous conditions, apricots showed a higher water loss, at the level of 4.68 g H2O/g i.d.m. At 25°C, after the first hour of dehydration, the energy value of saccharides in apricots was 315 kJ/100 g; at 55°C, after 3÷5 hours it fluctuated around 500 kJ/100g. Dehydrated chokeberry was characterized by approx. 1.5÷2 times lower energy value than apricot

Effect of osmotic dehydration in fructose, sucrose and fructooligosaccharide solutions on the content of saccharides in plums and apples and their energy value

Plums (Najbolia and Stanley) and apples (Idared) were subjected to osmotic dehydration in 50% solutions of fructose, sucrose and fructooligosaccharides (FOS) at 22, 40 and 60 °C for 24 hours. The content of fructooligosaccharides, sucrose and monosaccharides in dried material was determined. Plums osmosed in fructose contained from 22.3% w/w to 29.6%w/w of this saccharide depending on the process temperature. The content of sucrose in plums and apples varied from 18.6% w/w to 30.4% w/w after using sucrose as osmotic agent. Material processed at 40 °C was characterised by the highest content of FOS: 22.6 24.7% w/w in plums (nystose as osmotic agent) and 13.7% w/w in apples (FOS preparation as osmotic agent). The partial replacement of sucrose and monosaccharides by fructooligosaccharides reduced the energy value of carbohydrates in dried material by 12 37% depending on the process conditions.vo

Effects of Lactofermented Beetroot Juice Alone or with N-nitroso-N-methylurea on Selected Metabolic Parameters, Composition of the Microbiota Adhering to the Gut Epithelium and Antioxidant Status of Rats

An objective of this work was to assess the biological activity of beetroot juice (Chrobry variety, Beta vulgaris L. ssp. vulgaris), which was lactofermented by probiotic bacteria Lactobacillus brevis 0944 and Lactobacillus paracasei 0920. The oxidative status of blood serum, kidneys, and liver of rats consuming the fermented beetroot juice were determined. The experimental rats were divided into four groups on diet type: Basal diet, basal diet supplemented with fermented beetroot juice, basal diet and N-nitroso-N-methylurea treatment, and basal diet supplemented with fermented beetroot juice and N-nitroso-N-methylurea treatment. Mutagen N-nitroso-N-methylurea, which was added to diet in order to induce aberrant oxidative and biochemical processes and disadvantageous changes in the count and metabolic activity of the gut epithelium microbiota. The nutritional in vivo study showed that supplementing the diet of the rats with the lactofermented beetroot juice reduced the level of ammonia by 17% in the group treated with N-nitroso-N-methylurea. Furthermore, the positive modulation of the gut microflora and its metabolic activity was observed in groups of rats fed with the diet supplemented with the fermented beetroot juice. A concomitant decrease in the b-glucuronidase activity was a consequence of the gut epithelium microbiota modulation. The antioxidant capacity of blood serum aqueous fraction was increased by about 69% in the group of rats treated N-nitroso-N-methylurea mixed with the fermented beetroot juice and N-nitroso-N-methylurea versus to the N-nitroso-N-methylurea treatment, whereas the antioxidant parameters of the blood serum lipid fraction, kidneys, and liver remained unchanged

Synthesis of the Galactosyl Derivative of Gluconic Acid With the Transglycosylation Activity of β-Galactosidase

Bionic acids are bioactive compounds demonstrating numerous interesting properties. They are widely produced by chemical or enzymatic oxidation of disaccharides. This paper focuses on the galactosyl derivative of gluconic acid as a result of a new method of bionic acid synthesis which utilises the transglycosylation properties of β-galactosidase and introduces lactose as a substrate. Products obtained in such a process are characterised by different structures (and, potentially, properties) than those resulting from traditional oxidation of disaccharides. The aim of this study is to determine the effect of selected parameters (concentration and ratio of substrates, dose of the enzyme, time, pH, presence of salts) on the course of the reaction carried out with the enzymatic preparation Lactozym, containing β-galactosidase from Kluyveromyces lactis. Research has shown that increased dry matter content in the baseline solution (up to 50 %, by mass per volume) and an addition of NaCl contribute to higher yield. On the other hand, reduced content of the derivative is a result of increased pH from 7.0 to 9.0 and an addition of magnesium and manganese salts. Moreover, exceeding the β-galactosidase dose over approx. 35 000 U per 100 g of lactose also leads to reduced yield of the process. The most favourable molar ratio of sodium gluconate to lactose is 2.225:0.675. Depending on the conditions of the synthesis, the product concentration ranged between 17.3 and 118.3 g/L of the reaction mixture, which corresponded to the mass fraction of 6.64–23.7 % of dry matter. The data obtained as a result of the present study may be useful for designing an industrial process