Content of Total Phenolics, Flavan-3-Ols and Proanthocyanidins, Oxidative Stability and Antioxidant Capacity of Chocolate During Storage

Antioxidant (AO) capacity of chocolates with 27, 44 and 75 % cocoa was assessed after production and during twelve months of storage by direct current (DC) polarographic assay, based on the decrease of anodic current caused by the formation of hydroxo-perhydroxyl mercury(II) complex (HPMC) in alkaline solutions of hydrogen peroxide at potentials of mercury oxidation, and two spectrophotometric assays. Relative antioxidant capacity index (RACI) was calculated by taking the average value of the AO assay (the sample mass in all assays was identical). Oxidative stability of chocolate fat was determined by differential scanning calorimetry. Measured parameters and RACI were correlated mutually and with the content of total phenols (Folin-Ciocalteu assay), flavan-3-ols (vanillin and p-dimethylaminocinnamaldehyde assay) and proanthocyanidins (modified Bate-Smith assay). During storage, the studied functional and health-related characteristics remained unchanged. Amongst applied AO assays, the DC polarographic one, whose validity was confirmed by two-way ANOVA and F-test, correlated most significantly with oxidative stability (oxidation onset temperature and induction time). In addition, principal component analysis was applied to characterise chocolate types

Sensory and color properties of dietary cookies with different fiber sources during 180 days of storage

The aim of this study was to examine the sensory properties of dietary cookies produced with addition of different dietary fiber sources (inulin and oligofructose, oat flakes, mixture of oat flakes and whole meal flour, whole meal flour and mixture of whole meal flour and carob flour), and to measure instrumentally color changes of cookies upper and lower surfaces, after storage at temperatures of 18-20 °C for 180 days. Addition of inulin and oligofructose was determined to be the fiber source with the highest impact on sensory properties. Storage for 180 days expressed the highest influence on texture properties of dietary cookies regardless of applied dietary fiber source. Color differences calculated from measured color properties (psychometric light, L*, psychometric tone, a*, and psychometric chrome, b*) between products including different fiber sources were noticeable to extremely noticeable among products, with the most expressed difference was registered for products containing carob flour.Cilj istraživanja je ispitivanje senzornih karakteristika dijetetskog keksa proizvedenog sa dodacima dijetetskih vlakana iz različitih izvora (inulin i oligofruktoza, ražene pahuljice, mešavina raženih pahuljica i integralnog brašna, integralno brašno i mešavina integralnog brašna i brašna rogača) i instrumentalno merenje promena boje gornje i donje površine keksa, korišćenjem "Minolta" Chroma meter CR 400 tristimulus colorimeter tokom skladištenja na temperaturi od 18-20 °C do 180 dana. Za dodatak inulina i oligofruktoze je utvrđeno da je izvor dijetetskih vlakana koji je najviše uticao na senzorna svojstva. Skladištenje od 180 dana imalo je najveći uticaj na teksturne promene dejetetskog keksa, nezavisno od izvora dijetetskih vlakana. Razlike u boji izračunate na bazi instrumentalno merenih svojstva boje proizvoda (L*, a*, b*) izmeću proizvoda različitog sastava u pogledu izvora dijetnih vlakana su bile izražene do ekstremno izražene, sa najupečatljivijim razlikama registrovanim u slučaju dodatka brašna od rogača

Effect of goat breed on the meat quality

The quality of goat meat has recently become an important aspect in the marketing of goats in Serbia. The aim of this study was to compare some goat meat quality parameters of various races and to determine the differences between them. Goat breeds were Balkan goat and Serbian white goat, both female in the age of four years. Analysis of quality parameters: chemical composition (moisture, protein, total fat, ash,), pH value, fatty acids, amino acids, microelements content, tenderness, cooking loss and colour measurements were done. Statistically significant difference was found between the samples of two groups of goat meat (P < 0.05) in relation to: live weight (kg), water (%), fat (%), protein (%) and ash (%), among 11 of 15 tested fatty acids, amino acid leucin, sensory examination of fresh meat for the palpatory evaluated firmness and in the content of copper and zinc. Statistically significant differences between the groups did not existed regarding the pH value, fatty acids eicosenoic, cis-heptadecenoic, t-elaidic, t-linolelaidic and amino acids alanine, arginine, aspartic acid, cysteine, glutamic acid, glycine, histidine, isoleucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine. Also there was no statistically significant difference in instrumental testing of the meat color, sensory evaluation of surface color, visual evaluated structure, olfactory evaluated odor and iron and manganese. These results suggest that the race of animal has an impact on meat quality.Kozije meso ima otprilike istu hranljivu vrednost kao i ovčije (bliže rečeno više belančevina, a manje masti). Zbog niske zastupljenosti zasićenih masnih kiselina i holesterola, kozije meso u ishrani ljudi je zdravija alternativa u poređenju sa drugim vrstama crvenog mesa. Bez obzira na nutritivnu vrednost, ono je ipak manje cenjeno zbog specifičnog mirisa i ukusa koji su intenzivniji kod starijih životinja. U Srbiji se malo zna o kvalitetu kozijeg mesa u poređenju sa ostalim vrstama, a posebno je nedovoljno poznavanje kvaliteta mesa autohtonih rasa koza. Cilj ovog istraživanja bio je da se prikupe i uporede podaci hemijskog sastava, pH vrednosti, sastava masnih i amino kiselina, pojedinih mikroelemenata, boje i mekoće (instrumentalno), senzorne analize svežeg mesa i određivanje kala toplotne obrade srpske bele i balkanske koze iste starosti. Iz uzoraka m. longissimus dorsi, uzetih nakon klanja navedenih životinja, ispitivan je hemijski sastav i pH vrednost, primenom ISO metoda. Sastav masnih kiselina i određen je primenom gasne hromatografije (GC6890N, Agilent Tech., USA) i poređen je sa standardom masnih kiselina (standard mix of FAMEs 37, Supelco, USA). Aminokiseline u navedenim uzorcima određene su nakon hidrolize tkiva primenom AOAC metode 982.30. Određivanje mikroelemenata u mesu koza vršeno je u metodom AOAC method 999.10. Princip metode za određivanje kala toplotne obrade sastoji se u određivanju gubitka mase usled toplotne obrade uzorka. Određivanje mekoće je obavljeno aparatom Warner–Bratzler. Boja svežeg mesa je takođe određivana u m. longissimus dorsi upotrebom Minolta chromameter CR-400. Senzornu analizu su radili obučeni ocenjivači u skladu sa ISO metodom. Dobijeni rezultati su statistički obrađeni primenom programa MS-Excel 2003, ANOVA, i utvrđene razlike srednjih vrednosti poređene t-testom na nivou značajnosti 99 i 95%. Na osnovu dobijenih rezultata može se zaključiti da je postojala statistički značajna razlika u kvalitetu mesa između ispitivanih uzoraka