Discrimination of roast and ground coffee aroma

Background: Four analytical approaches were used to evaluate the aroma profile at key stages in roast and ground coffee brew preparation (concentration within the roast and ground coffee and respective coffee brew; concentration in the headspace of the roast and ground coffee and respective brew). Each method was evaluated by the analysis of 15 diverse key aroma compounds that were predefined by odour port analysis. Results: Different methods offered complimentary results for the discrimination of products; the concentration in the coffee brew was found to be the least discriminatory and concentration in the headspace above the roast and ground coffee was shown to be most discriminatory. Conclusions: All approaches should be taken into consideration when classifying roast and ground coffee especially for alignment to sensory perception and consumer insight data as all offer markedly different discrimination abilities due to the variation in volatility, hydrophobicity, air-water partition coefficient and other physicochemical parameters of the key aroma compounds present

Influence of the type of fat and air humidity on chosen properties of the lipid fraction in the process of baking shortbread pastries

The results from his study reveal that the type of fat used during the baking of shortbreads had a noticeable influence on the properties of lipid fractions as well as the correlation among these properties (acid value, peroxide value, conjugated dienes and trienes contents). 
 For low-<i>trans</i> fats, the correlation between acid value and peroxide value was inversely proportional; for transcontaining fats this correlation was directly proportional. 
 An increase in air humidity during baking caused a decrease in the melting temperature of the fractions of fats used in the process, compared to fats from pastries baked in dry air. This may be indicative of a product with a high degree of unsaturation in the lipid fraction.<br><br>Los resultados de este estudio demuestran que el tipo de grasa utilizada en el horneado de mantecadas tienen una influencia evidente en las propiedades de la fracción lipídica y una correlación entre estas propiedades (acidez, peróxidos, dienos y trienos conjugados).
 Para grasas bajas en <i>trans</i> la correlación entre la acidez y el índice de peróxido es inversamente proporcional, para grasas conteniendo <i>trans</i> esta correlación fue directamente proporcional.
 Un aumento de la humedad del aire durante el horneado causa una disminución de la temperatura de fusión de las fracciones de grasas utilizadas en el proceso, en comparación con las grasas de repostería horneadas en aire seco. Esto puede indicar la presencia de productos con alto grado de insaturación en las fracciones lipídicas