Valutazione delle caratteristiche fisiche e strutturali di un prodotto da forno durante la conservazione (Spianata di Ozieri)

The aim of this research was the characterization by physical and structural properties, a typical bakery product (Spianata di Ozieri). The samples of two differents kind of spianata were submitted to dynamometric analysis (texture profile analysis - TPA, cut and tension test), color measurement and microbiological tests over 14 days of storage time at 22°C. Three samplings were conducted in different periods of the year to test the seasonality of the production. A collaborative test was carried out at the DISAABA (Sassari University) and in the laboratories of Food Science & Technology (Bologna University). The most important results obtained in this research confirm effectivement that this kind of product is really typical and so the data variability obtained is quite normal. The microciological tests showed a good quality of the product during the normal storage time. Lo scopo di questa ricerca è stato quello di effettuare una prima caratterizzazione fisica e strutturale di un prodotto da forno tipico sardo, la spianata di Ozieri. In particolare, sono state studiate le variazioni di alcune caratteristiche strutturali dinamometriche, fisiche e chimico-fisiche e l'evoluzione della carica microbica durante la conservazione, a temperatura controllata di 22°C circa, di due diversi campioni commerciali di spianata sarda, realizzati artigianalmente e confezionati con metodologie diverse: uno in atmosfera ordinaria e destinato al mercato locale e l'altro confezionato in atmosfera protettiva (40% anidride carbonica, 60% azoto) e destinato alla grande distribuziooe. Sono stati effettuati tre campionamenti nei mesi di luglio, novembre e gennaio, per valutare eventuali differenze dovute alia stagionalità di produzione. Le prove sono state condotte in collaborazione tra i laboratori del Disaaba dell'Università di Sassari e del Corso di Laurea in Scienze e Tecnologie Alimentari di Cesena, Università di Bologna. Sono stati analizzati i campioni delle due differenti produzioni e dei tre diversi campionamenti stagionali, valutando le modificazioni delle caratteristiche fisiche in conservazione, mentre l'evoluzione della carica microbica è stata valutata sulla campionatura di gennaio. Si riporteranno di seguito, i risultati ottenuti durante il periodo di osservazione, della durata di 14 giorni per campioni confezionati in atmosfera ordinaria e di 27 giomi per quelli condizionati in atmosfera protettiva

Dough thermo-mechanical properties: influence of sodium chloride, mixing time and equipment

Thermo-mechanical properties of doughs prepared from common wheat flour were investigated under different kneading conditions and with different amounts of sodium chloride. Dynamic mechanical thermal analysis showed that high-speed mixing and the addition of salt to dough slowed heat-induced reactions such as starch gelatinisation and protein coagulation. The effect of dough mixing technology was more significant than the amount of sodium chloride in modifying dough theological characteristics

Spaghetti cooking by microwave oven: Cooking kinetics and product quality

The cooking kinetics of spaghetti cooked in boiling water by a traditional method: (TRC) and by microwave (MWC) using an innovativeoven suitable for pasta cooking were investigated. The quality of cooked spaghetti was studied as a function of the following cookingparameters: weight increase, total thermal effect and gelatinization extent.Microwave cooking resulted in a time–temperature profile different from that of the traditional cooking process and when the cookingparameters were equal, the microwave cooking was characterized by a lower total thermal effect.In spite of the lower total thermal effect, when the weight increase was equivalent, microwave cooking resulted in more gelatinized andsofter products than traditional cooking. The higher gel degree and amylose solubility were not reflected in a higher cooking loss or stickiness;this was due to a more compact gluten network in the outer layer of spaghetti.By modulating the cooking time it was possible to obtain MWC samples with values of weight increase, gel degree and firmness,respectively, equal to the TRC ones; thus different ‘‘optimum cooking times” were defined. Sensory panels did not perceive any significantdifferences between TRC spaghetti and MWC spaghetti samples cooked for different ‘‘optimum cooking times” except for the yellowcolour intensity, which resulted higher for MWC pasta in agreement with the instrumental analysis data.[...

Characteristics of bread making doughs: influence of sourdough fermentation on the fundamental rheological properties

The proofing process is an essential step in the bread making technology in providing a link between the bubble structure created in the mixer and the final baked loaf structure. This research was carried out to test the effect of two different types of fermentation on bread making dough properties. Fundamental rheological tests were used to evaluate and compare doughs prepared by using compressed yeast and only natural yeast. Dynamic oscillation tests were performed using a controlled stress\u2013strain rheometer; the phase angle (\u3b4) and the value of the storage modulus (G) were measured for all samples. Significant differences were found between the doughs which were made using commercial compressed yeast (baker\u2019s yeast (BY)) and those prepared using sourdough (SD). In particular SD was less elastic, less firm and easily extensible having higher phase angle and lower G