On the quality control of ‘olive paste’, a specialty based on olives and olive oil

Abstract

Abstract‘Olive paste’ is a preserved food gaining popularity as a gourmet product. Its quality depends on that of the major ingredients, table olives (green or black) and virgin olive oil, as well as on the changes occurring to the constituents of the latter during preparation and storage. In this view, our attention was focused on the characteristics of the lipid fraction (l.f.) of a great number of commercial products after a careful search in retail markets and the web. Ultraviolet absorbance values (K232, K270) of the l.f., a criterion set for edible and non‐edible olive oil oxidative status due to paste heat treatment during pasteurization, could not support the label information regarding the quality of the oil used. On the contrary, the content of α‐tocopherol (˜250 mg/kg l.f. or ˜50 mg/kg paste) was a strong indication of good‐quality major ingredients. Within each brand, consistency with labeling was checked through squalene (higher content in products containing higher amounts of olive oil) or β‐carotene determination (higher levels in preparations containing red pepper). For green olive paste samples, the values of the ratio pheophytin a/pyropheophytin a may be used to monitor the shelf life of the product. The findings support routine quality control of the new product.

Varietal and Geographical Discrimination of Greek Monovarietal Extra Virgin Olive Oils Based on Squalene, Tocopherol, and Fatty Acid Composition

“…Squalene is known to occur in concentrations between 200 and 7500 mg/kg, although much higher levels (up to 12,000 mg/kg) have been reported [ 3 ]. Good-quality Greek olive oils have been found to have average squalene concentration between 2000 and 7000 mg/kg [ 8 , 15 ], and within this range, olive oils from Spain, Italy, and the northern Adriatic region have also been reported [ 9 , 31 , 32 ].…”

“…There is controversial evidence that squalene plays a rather confined role in olive oil stability even at low temperatures [ 5 ]. Diverse chromatographic techniques have been used to determine squalene content such as High-Performance Liquid Chromatography (HPLC) [ 6 , 7 , 8 ] and Gas Chromatography (GC) [ 9 , 10 , 11 ] after its extraction with the use of organic solvents.…”

Effects of pasteurisation and storage on quality characteristics of table olives preserved in olive oil

“…In the olive paste, the increase in K270 was less accentuated, instead reaching values of absorbance of about 0.20 after 3 months of storage. Anniva & Tsimidou () observed the same situation (low K232, high K270) in their 42 samples of olive paste from a Greek market (without knowing the history of the samples), and they conjectured that their observations derived from the decomposition of the hydroperoxides to secondary oxidation products. Mucciarella & Marsilio () also reported a notable increase in K270 in olives preserved in olive oil during storage.…”

“…Relevant information can be also drawn from the respective characteristics of the major ingredients used in their production, such as, in the present case, the olive oil. The quality of this type of end product essentially depends on the quality of this major ingredient, as well as on the changes that can occur during the preparation and storage (Anniva & Tsimidou, ; Schwartz et al ., ). In particular, these changes can include the impact of thermal treatments, such as pasteurisation, on the composition and the oxidative stability of the olive oil (Brenes et al ., ; Allouche et al ., ).…”

Physicochemical and antioxidant characteristics of gingerbread plum (<em>Neocarya macrophylla</em>) kernel oils

“…Flavonoids can directly react with superoxide anions and lipid peroxyl radicals and consequently inhibit or break the chain of lipid peroxidation. In the case of β-carotene, some authors reported values of 6.43 mg·kg −1 and 5 mg·kg −1 for extra virgin olive oil (Anniva and Tsimidou, 2009). …”