## 3 Results and Discussion
### Phosphorus and Phytic Acid Content  
The phosphorus and phytic acid content of the olive cakes analysed is listed in Table 3. The table presents the levels of total phosphorus and phytic acid in different types of olive cakes. Total phosphorus refers to the overall content of phosphorus in the samples, while phytic acid represents a specific form of phosphorus found in plant-based foods. Observing the data, it is evident that there are variations in both total phosphorus and phytic acid levels among the different types of olive cakes. For total phosphorus, EOC 2 displays the highest concentration, followed by TPOC (pitted) and TPOC (dehydrated). COC 1 and COC 2 exhibit similar levels of total phosphorus, while EOC 1 has the lowest concentration. These differences could be attributed to factors such as olive variety, soil composition and agricultural practices. Phytic acid levels also vary among the samples, with EOC 2 showing the highest concentration, followed by COC 1 and COC 2. TPOC (pitted) and TPOC (dehydrated) exhibit intermediate levels of phytic acid, while EOC 1 has the lowestconcentration. Phytic acid is known to be an antinutrient that can inhibit the absorption of minerals such as iron and zinc in the body. Therefore, higher levels of phytic acid in certain olive cakes could have implications for their nutritional value and bioavailability of minerals. Overall, the data highlight the importance of considering both total phosphorus and phytic acid levels in olive cakes as they can impact nutritional quality and potential applications in various industries such as food and agriculture. Further research is needed to understand the factors influencing phosphorus and phytic acid levels in olive cakes and their implications for human health and the environment. Phosphorus and phytic acid play crucial roles in plant materials, bearing significant nutritional and processing implications within olive cake. Phytic acid serves as the primary form of phosphorus storage in seeds and fruit, although it is less common in leaves. Nevertheless, when accurately measured, it is almost always detectable, constituting approximately 7.6% of total phosphorus [58]. During growth, seeds accumulate phosphorus beyond cellular requirements, which plants then convert into phytic acid (myo-inositol-1,2,3,4,5,6-hexakishosphate or InsP6) [59]. In mature seeds, phytic acid stores roughly 60-80% of total phosphorus. However, its complex structure renders it unavailable for direct absorption by humans and nonruminant animals. Since many of these organisms lack phytase, the enzyme required to degrade phytic acid and release phosphorus, mineral deficiencies may occur. Additionally, phytic acid acts as a potent chelator of Fe, Mg and Ca, further impacting mineral absorption [60, 61, 62]. Data regarding the presence of phytic acid in the olive oil industry by-products and olive oil itself have yet to be consolidated and critically analysed comprehensively. In their examination of the literature on phytic acid content in leaves, [PERSON] and [PERSON] identified 45 published studies in which phytic acid was consistently detected whenever specifically investigated, constituting up to 98% of total phosphorus [61]. The absence of a commercially feasible, straightforward and quantitative method for phytic acid analysis has posed a significant hurdle to its accurate quantification. Although the widely accepted AOAC 986.11 method is valuable, it comes with limitations that impede its universal application. One major drawback is the necessity for a complex anion exchange purification step for each analysis. This step can be time-consuming, labour-intensive, error-prone and generates chemical waste. Another critical concern is the assumption made by this method that only phytic acid is purified during the anion exchange step. While this may hold true for unprocessed grains, where phytic acid constitutes the majority of inositol phosphates (at least 97%), it is not valid for processed foods and feeds.