Effect of continuous cooking on cooking water properties and pasta quality

BACKGROUND Professional pasta cookers are filled with fresh water. The solids leached from the cooked pasta make pasta less firm and stickier while leading to changes in water properties and overflow. Added fresh water then has to be reheated. The effect of continuous cooking on cooked pasta quality and water properties was investigated for the first time by simulating professional pasta cooking on a laboratory scale. RESULTS Continuous cooking procedure of 12 batches led to a solid content of cooking water of 37gkg(-1), resulting in an increase in shear-thinning behaviour and consistency index. Pasta cooking loss decreased from 52.7 to 35.7gkg(-1) due to the lower water concentration gradient through the pasta. This was confirmed by a decrease in swelling index from 2.0x10(-3) to 1.6x10(-3)gkg(-1) during the optimal cooking time (13min 45s). Surprisingly, continuous cooking made the pasta firmer while stickiness did not differ significantly (P>0.05). CONCLUSION Taking batch number 7 as the acceptability threshold, further studies are required to find an optimal solution for retaining cooking water properties highly affecting daily cooking procedures in food service kitchens. (c) 2018 Society of Chemical Industr

Effect of high pressure homogenization and high power ultrasound on some physical properties of tomato juices with different concentration levels

The effect of high pressure homogenization (HPH) and ultrasound (US) on rheological properties, color, precipitate weight ratio, pectin esterification degree and cell integrity of tomato juices with different soluble solids content (5.0, 7.5, 10.0 Brix) was studied. Samples were subjected to HPH up to 150 MPa or US up to 30 min. The energy efficiency associated to the processes was also evaluated. Results showed that stress type and product concentration influenced the changes of tomato juice physical properties. In particular, HPH and US treatments were responsible for higher G0 and consistency of processed tomato juices than untreated samples. Increases in sample rheological properties were comparable for the 5.0 and 7.5 Brix treated HPH and US samples, whereas HPH was more effective than US in the case of 10.0 Brix sample. These changes were in agreement with other indexes, i.e. precipitate weight ratio increase and cell integrity decrease, and were attributed to stronger of inter-particle interactions. The process energy efficiency showed that lower energy was involved in HPH in comparison to US

Properties of Dried Apricots Pretreated by Ultrasound-Assisted Osmotic Dehydration and Application of Active Coatings

Research background. The worldwide demand for healthy and sulphur-free dried vegetables and fruits has grown. Combined ultrasound-assisted osmotic dehydration (UOD) and application of active coatings incorporating natural preservatives represents an attractive alternative for sulphuring process to preserve the sensorial and nutritional quality of dried fruits. The aim of this study was to investigate the effect of osmotic dehydration (OD) and UOD and the use of pectin coatings (alone or with citric acid, CA or ascorbic acid, AA) on physical, textural and microstructural properties of hot air-dried apricot. Experimental approach. Fresh apricot cubes (1 cm3) were pre-treated with either OD at a temperature of 55 °C for 30 and 45 min or UOD at two ultrasonic frequencies of 25 and 35 kHz for 30 and 45 min followed by application of active coatings with pectin alone, pectin + CA or pectin + AA for 10 min. All pre-treated coated samples were then hot-air dried at a temperature of 60 °C until a final moisture content of 20 % (wet basis) was reached. Physical (shrinkage, apparent and bulk densities), chemical (browning value, water activity), textural (firmness and shrinkage), microstructure and microbial load of dried apricot was studied. Results and conclusions. Application of OD and UOD improved physical and textural properties of the dried apricots. Moreover, apparent and bulk densities, rehydration capacity of OD and UOD pre-treated samples were increased. While, shrinkage, water activity and microbial load were decreased. Firmness of UOD pre-treated samples was significantly (p < 0.05) lower than that of OD ones. Likewise, increasing ultrasound frequency from 25 to 35 kHz led to a significant decrease in Fmax values of dried apricots. Furthermore, coating of the OD and UOD processed samples with pectin + CA increased Fmax and decreased rehydration capacity of dried apricots. Scanning electron microscopy of both OD and UOD samples illustrated improvement of textural properties. The utilization of both OD pre-treatment and pectin edible coatings resulted in a decrease in browning values. However, UOD increased browning values of the dried apricots. Coating of UOD samples with pectin + AA resulted in substantial discoloration in hot air-dried apricot. Novelty and scientific contribution. This study advances the knowledge in the field of fruit drying by combined application of OD or UOD pre-treatments with post-treatments with active edible coatings on different properties of hot-air dried apricot

Dalla Farina alla Comunit\ue0

L\u2019attuale crisi di sistema economica, sociale e ambientale ha spinto molte persone ad interrogarsi sull\u2019attuale modello di produzione e consumo, basato su un sovra sfruttamento delle risorse e su un consumismo sfrenato. In diverse parti del modo si stanno sperimentando pratiche che, seppure molto diverse tra loro, sono orientate verso un obiettivo comune: riportare l\u2019economia entro una dimensione in cui le comunit\ue0 si riconoscono e si relazionano con il territorio come elemento fondamentale a cui ricondurre i bisogni essenziali. Tutte queste pratiche sono raccolte e descritte come elementi costituenti dell\u2019\u2019economia solidale\u2019 fondata su una pluralit\ue0 di principi come il mutualismo, la cooperazione, la sostenibilit\ue0, la democrazia e la giustizia. Anche nella regione Friuli Venezia Giulia si sono avviate pratiche in cui le relazioni di scambio tra cittadini \u2018produttori e consumatori\u2019 sono state riportate alla fiducia reciproca e alla assunzione di responsabilit\ue0 attraverso la sottoscrizione di un \u2018patto\u2019. Il libro descrive una di queste esperienze in cui elementi centrali sono il grano, la farina, il pane e la comunit\ue0

Effetto dell’aggiunta di inulina sulle proprietà reologiche e panificatorie di impasti di frumento

The effect of inulin addition on the rheological properties of wheat doughs and bread quality was evaluated. The influence of polymerisation degree (DP) of fructans was investigate using three commercial products (Raftiline ® ST: DP 10; Raftiline ® HP and Raftiline ® HP gel: DP 23). Inulin contents from 2.5 to 7.5% on dry matter as wheat flour plus inulin were used. Fibre addition increased mixing time and dough stability and decreased softening degree and farinograph water absorption, which depend on DP. Bread quality was evaluated using loaf volume, crumb moisture and texture

Impact of oleuropein on rheology and breadmaking performance of wheat doughs, and functional features of bread

Oleuropein (OP) is a polyphenol present in drupes and leaves of olive tree with health benefits and, as antioxidant, potentiality to alter gluten functionality. Effects of OP inclusion to wheat flour (0.01% and 0.02% on flour weight basis) on dough rheology and breadmaking performance, and bread features were investigated. Farinograph, uniaxial extension and shear rheometry (oscillatory and creep-recovery) were applied. Doughs containing OP were stronger, more elastic, and less sticky indicating the ability of OP to act as flour improver. The strengthening effect of OP on gluten led to the increase in bread volume and softer crumb compared to control. A lower crumb density of bread with the addition of OP was related to a higher in vitro glycaemic response. An increase in the antioxidant capacity of bread made with the phenolic compound was also found

Studio dei cambiamenti strutturali del formaggio tipo stracchino in conservazione

The aim of this work was to evaluate structure changes in Stracchino cheese during storage using rheological measurements. Three packaging materials were used: 1) cellophane-polyethylene as a reference package commonly use for this product (R); 2) calcium polycarbonate and HDPE (Ovtene, OV); 3) active Ovtene, obtained by addition of potassium sorbate to OV (AOV). Product structure was evaluated using rheological oscillatory measurements in linear viscoelastic range (frequency sweep test) over 28 days