Analyses of Olive Oil in Tuscany in the 2023 season

We have now reached the end of the 2023 oil season, so we can make the annual considerations on the quality and quantity of oil produced this year. The productivity aspect is becoming increasingly important in this sector in recent years and, as in many other sectors, when production is low, quality becomes a secondary aspect.

In Tuscany, the season that has just ended showed a much lower production than last year and compared to its historically expressed potential. This situation occurred in almost the entire central/northern area, while in the south the harvest was better and increased compared to the previous oil season.

Also this year, it was climatic factors in addition to the alternate bearing - ON years/OFF years - that negatively affected productivity in the central/northern area. In particular, the latter part of spring was too rainy, hindering fruit set, and the now usual summer drought further worsened the situation.

In addition, the olive fly arrived in the olive groves in Tuscany at the end of the summer, but it did not cause any serious problems for olive growers, who pressed quickly after the harvest.

Although the environmental conditions were not favourable, the quality of the oil, at least in Tuscany, was decent.

These are the data of the oils analysed with CDR OxiTester:

The results in the table are ordered according to the value of total polyphenols, which we can consider the most indicative parameter of oil quality.

In general, the quality of the olive oils analysed proved to be medium to high.

The polyphenol value averaged 466mg/Kg, slightly lower than last year, and the acidity value was a little higher: 0.24% compared to last year's 0.22%. Nevertheless, these are values that indicate a high quality product.

The  peroxide value of all samples analysed was also largely below the limit required to classify the product as extra virgin.

Years such as this one in which production is lower can increase the risk of fraud because prices rise in some areas and market demand can more easily attract misbehaving sellers.

Analyses obviously allow to certify the quality of the oil produced/purchased and in particular the spectrophotometric analysis of the K270 can help to detect grosser frauds.

Determining the K270 value gives a measure of the oil's stability in relation to oxidation and chemical alteration, and is particularly helpful in detecting potential fraud in olive oil. For example, a high K270 value indicates a significant level of oxidation (also detectable with the peroxide test), which can be caused by various factors, including the ageing of the oil or its exposure to sub-optimal storage conditions.

Counterfeit or adulterated products often contain low-quality olive oils, sometimes refined or mixtures of olive oil with other types of vegetable oils, such as sunflower oil or rapeseed oil (canola oil). These oils, which are used for counterfeiting, may have a higher K270 value than high-quality extra virgin olive oil so that by measuring this parameter, such mixtures or adulterations can be identified.