Has the use of talc an effect on yield and extra virgin olive oil quality?

The maximization of both extraction yield and extra virgin olive oil quality during olive processing are the main objectives of the olive oil industry. As regards extraction yield, it can be improved by both acting on time/temperature of malaxation and using physical coadjuvants. It is well known that, generally, increasing temperature of malaxation gives an increase in oil extraction yield due to a reduction in oily phase viscosity; however, high malaxation temperature can compromise the nutritional and health values of extra virgin olive oil, leading to undesirable effects such as accelerated oxidative process and loss of volatile compounds responsible for oil flavor and fragrance. The addition of physical coadjuvants in olive oil processing during the malaxation phase, not excluded by EC regulations owing to its exclusively physical action, is well known to promote the breakdown of oil/water emulsions and consequently make oil extraction easier, thus increasing the yield. Among physical coadjuvants, micronized natural talc is used for olive oil processing above all for Spanish and Italian olive cultivars. The quality of extra virgin olive oil depends on numerous variables such as olive cultivar, ripeness degree and quality, machines utilized for processing, oil storage conditions, etc. However, the coadjuvants utilized in olive processing can also influence virgin olive oil characteristics. The literature highlights an increase in oil yield by micronized natural talc addition during olive processing, whereas no clear trend was observed as regards the chemical, nutritional and sensory characteristics of extra virgin olive oil. Although an increase in oil stability was reported, no effect of talc was found on the evolution of virgin olive oil quality indices during storage. © 2016 Society of Chemical Industry     

A by-product from virgin olive oil production (pâté) encapsulated by fluid bed coating: evaluation of the phenolic profile after shelf-life test and in vitro gastrointestinal digestion

Pâté is a by-product of virgin olive oil production presenting a high phenolic content and beneficial health effects. This research aims to evaluate the storage stability of phenolic compounds of pâté and a coated formulation, and to verify the bioaccessibility of the phenolic compounds. An accelerated shelf-life test at 40 °C/75% relative humidity was carried out for 75 days. Different combinations of degradative and hydrolytic reactions impacted the results. Indeed, at the end of the storage period, 84% of phenols was recovered in pâté with free tyrosol and hydroxytyrosol showing an increase due to secoiridoids hydrolysis. The total phenolic content of coated pâté did not significantly decrease, showing a higher increment of free tyrosol and hydroxytyrosol. Simulated digestion led to the liberation of 15% of phenols by both samples. In conclusion, the coating process improved the stability of pâté phenolic compounds without affecting their bioaccessibility.     

A Meta‐Analysis of Enriched Pasta: What Are the Effects of Enrichment and Process Specifications on the Quality Attributes of Pasta?

Pasta products enriched with ingredients to improve their nutritional value or functionality have become increasingly popular, and substantial research efforts have been directed towards the development of new enriched pasta products. In this work, a meta‐analysis was conducted to quantify the impact of enrichment and process specifications on the quality attributes of pasta. A literature search revealed 66 studies on enriched pasta. Process specifications and quality attributes, namely proximate composition, dough, drying, cooking, and mechanical properties, color, and sensory attributes, were extracted from the studies and compiled in a data set. Analysis of the data set revealed significant differences between pasta enriched with high‐fiber ingredients and pasta enriched with pulse flour. High‐fiber ingredients generally preserved the quality attributes of pasta more effectively than pulse flour. Comparisons based on the drying temperature showed that high drying temperatures generally improve the cooking properties of enriched pasta. Sensory evaluations indicated that enrichment levels below 10% generally do not affect consumer acceptance, but higher enrichment levels significantly decrease it. Pearson correlation coefficients showed that the gelatinization temperature and Farinograph properties are useful indicators of the mechanical properties and sensory attributes of pasta. The meta‐analysis revealed the need to better understand the impact of the processing history of the enrichment ingredient on the quality attributes and the health benefits of enriched pasta.