EFFECT OF SHOCK FREEZING OF DOUGH ON THE TECHNOLOGICAL PROPERTIES OF PUFF PASTRY ENRICHED WITH SUGAR BEET FIBER AND CHIA SEED (Salvia hispanica)

U cilju zadovoljena trendova u pekarskoj proizvodnji u ovoj disertaciji ispitan je efekat šok zamrzavanja na kvalitet peciva sa dodatkom integralnog pšeničnog brašna obogaćenog vlaknima šećerne repe i čija semenom. Istraživanja su sprovedena u četiri faze, pri čemu je u prve tri faze ispitivan uticaj ulaznih faktora na tehnološka svojstva testa i fizičke (zapremina, čvrstoća, narastanje, skupljanje, eliptičnost) i senzorske (metoda bodovanja i QDA metoda) parametre kvaliteta peciva. U prvoj fazi istraživanja izvršena je optimizacija sirovinskog sastava osnovnog i laminiranog testa. Primenom fundamentalnih reoloških merenja utvrđeno je da dodatak 1% vitalnog glutena značajno doprinosi postizanju odgovarajuće elastičnosti, deformacione prilagodljivosti na dejstvo napona, maksimalne popustljivosti puzanja i najmanjim njutnovskim viskozitetom osnovnog i laminiranog testa. Ispitivanjem uticaja količine margarina za laminiranje (40, 50 i 60%) i aditiva (0,5, 1 i 1,5%) kao ulaznih faktora, utvrđeno je da se optimalna žilavost i rastegljivost laminiranog testa, narastanje oko 5, specifična zapremina iznad 2,5 cm3/g, mala čvrstoća ispod 20 kgs i vrlo dobar senzorski kvalitet lisnatog peciva postiže dodatkom 60% margarina za laminiranje i 0,5% aditiva. Na bazi rezultata druge faze istraživanja primenom funkcije poželjnosti izvršena je optimizacija temperature zamrzavanja – tz (-25, -30 i -35°C)i temperature u središtu testanog komada – tt (-10, -15 i -20°C). Zamrzavanje lisnatog testa na temperaturi -35°C do postizanja tt -10°C je optimalni i najkraći režim zamrzavanja (15 min i 30 s), sa najmanjim negativnim efektom na fizičke i senzorske parametre kvaliteta lisnatog peciva. Treća faza uključila je optimizaciju sirovinskog sastava zamrznutog lisnatog testa obogaćenog vlaknima šećerne repe (0, 5 i 10%) i čija semenom (0, 3 i 6%). Treći ulazni faktor u ovoj fazi istraživanja bio je ksantan (0, 0,25 i 0,5%). Na osnovu eksperimentalnih rezultata i njihove statističke obrade utvrđeno je da je u cilju smanjenja negativnog efekta šok zamrzavanja i skladištenja na kvalitet proizvoda od zamrznutog lisnatog testa optimalan dodatak 2,25% vlakana šećerne repe, 3,6% čija semena i 0,5% ksantana. Pri pomenutom sastavu nastaju najmanje promene reoloških svojstava testa tokom zamrzavanja i skladištenja u odnosu na kontrolni uzorak. Pored vrlo dobrih fizičkih osobina i senzorskog kvaliteta lisnatog peciva nakon 30 i 120 dana skladištenja zamrznutog testa na temperaturi -18°C, pomenuti sirovinski sastav obezbeđuje i poboljšanje nutritivne vrednosti peciva. Sadržaj ukupnih prehrambenih vlakana iznad 6,0 g/100 g, kao i odgovarajuća količina minerala Mn, Fe, Mg i Zn omogućava upotrebu nutritivnih izjava „bogat vlaknima“, „bogat manganom“ i „izvor gvožđa, magnezijuma i cinka“ pri deklarisanju zamrznutog testa ili peciva. U četvrtoj fazi urađena je ekonomska analiza proizvodnje lisnatog peciva optimalnog sadržaja vlakana šećerne repe, čija semena i ksantana. Utvrđeno je da cena proizvoda ne može biti na nivou cene standardnog peciva sa dodatkom integralnog brašna, međutim, kao nosilac više nutritivnih izjava, pomenuto pecivo pripada grupi funkcionalnih proizvoda čija je cena na tržištu mnogo veća.In the aim to meet the trends in baking industry, the influence of shock freezing on the quality of puff pastry with added whole wheat flour and enriched with sugar beet fibers and chia seeds was investigated in this doctoral thesis. The experiments were conducted in IV phases, while the effects of input factors on the technological properties of dough and physical (volume, firmness, lift, shrinkage, ellipticity) and sensory (point-based and QDA method) quality parameters of puff pastry were investigated in the first three phases. In the first phase, the raw material composition of base and laminated dough was optimized. By the application of fundamental rheological measurements it was established that the addition of 1% of vital gluten significantly contributes to achieving of adequate elasticity, deformational adaptability to stress, maximum creep compliance and the lowest Newtonian viscosity of the base and laminated dough. By the examination of the influence of input factors, quantity of roll-in margarine (40, 50 and 60%) and puff pastry additive (0.5, 1 and 1.5%), it was determined that the optimal toughness and extensibility of laminated dough, as well as lift around 5, specific volume above 2.5 cm3/g, low firmness under 20 kgs and very good sensory quality of puff pastry was achieved by the application of 60% of roll-in margarine and 0.5% of puff pastry additive. Based on the results from second phase of the investigation, freezing temperature – tz (-25, -30 and -35°C) and temperature in dough center – tt (-10, -15 and -20°C) was optimized using desirability function. The application of freezing temperature -35°C while reaching the tt -10°C was the optimal and also shortest freezing regime (15 min and 30 s) and had the lowest negative effects on physical and sensory pastry quality parameters. The third phase consisted of the optimization of raw material composition of frozen puff pastry dough enriched with sugar beet fibers (0, 5 and 10%) and chia seeds (0, 3 and 6%). The third input factor in this phase of investigation was xanthan (0, 0.25 and 0.5%). Based on the results and statistical analysis it was determined that the addition of 2.25% of sugar beet fibers, 3.6% of chia seeds and 0.5% xanthan was optimal in terms of reducing the negative effect of shock freezing and storage on the quality of frozen product. With the mentioned composition, the smallest changes in the rheological properties of the dough occurred during freezing and storage in comparison to the control sample. Beside very good physical properties and sensory quality of puff pastry after 30 and 120 day of storage at -18°C, mentioned composition also provided the enhancement of nutritive value of puff pastry. Total dietary fiber content above 6.0 g/100 g, as well as corresponding amount of minerals Mn, Fe, Mg and Zn allows the use of nutritional statements “high-fiber”, “high in manganese” and “source of iron, magnesium and zinc” when writing the declaration for the frozen dough or pastries. In phase four the economic analysis of the production of puff pastry with optimal content of sugar beet fibers, chia seeds and xanthan was done. It was established that price of this product cannot be at the price level of a standard puff pastry with the addition of whole wheat flour. However, as a carrier of several nutritional statements, the mentioned pastry belongs to the group of functional products whose market price is much higher