Q2. How many ml/min was used for chromatographic analysis?
HPLC-DAD/MS system for anthocyanins identificationChromatographic separation was carried out on a LiChroCART column (250 · 4 mm, RP-18, 5 lm particle size, Merck, Darmstadt, Germany), using the solventsystem water–formic acid (19:1) (A) and methanol (B), starting with 5% methanol and installing a gradient to obtain at 3 min – 15% B, 13 min – 25% B, 25 min – 30% B, 35 min – 35% B, 39 min – 40% B, 42 min – 45% B, 45 min – 45% B, 50 min – 47% B, 60 min – 48% B, 64 min – 50% B and 66 min – 100% B.
Q3. What is the common type of luteolin in olives?
In 25, out of the 29 analysed samples, luteolin 7-O-glucoside and rutin were the predominant flavonoids and, in general, rutin was present in higher amounts than the luteolin derivative.
Q4. what are the important classes of phenolic compounds in olives?
The most important classes of phenolic compounds in olive fruit include phenolic acids, phenolic alcohols, flavonoids and secoiridoids (Macheix, Fleuriet, & Billot, 1990; Ryan & Robards, 1998; Soler-Rivas, Esp ın, & Wichers, 2000).
Q5. What is the effect of the geographical origin on the composition of olives?
If future analysis confirms the results now obtained, the authors can conclude that at least two Portuguese cultivars may produce excellent olive oils in terms of oxidative resistance, given their very high levels of hydroxytyrosol and oleuropein, two compounds that are considered to give strong protection against autoxidation and thermoxidation of olive oil (Papadopoulos & Boskou, 1999).
Q6. What was the mass of the cyanidin aglycone?
Upon HPLC–MS analysis, peak 4 showed a pseudomolecular ion [M+H]þ at m=z 449 and the MS2 event yielded a fragment ion at m=z at 287, typical mass in the positive mode of the cyanidin aglycone, corresponding to the loss of glucose (m=z 162).
Q7. What is the name of the phenolic alcohols in olives?
The phenolic alcohols of olives are 3,4-dihydroxyphenylethanol (hydroxytyrosol) and p-hydroxyphenylethanol (tyrosol) (Macheix et al., 1990;* Corresponding author.
Q8. How many different olive cultivars were collected?
Olive fruits (Tables 1–3) were collected from different locations in north (Macedo de Cavaleiros, Mirandela, Valpac os, Mogadouro and Figueira de Castelo Rodrigo) and central Portugal (Fund~ao and Castelo Branco), yielding a total of 29 samples from 18 different cultivars.
Q9. What is the reason for the high levels of anthocyanins in Negrinha?
The high levels of anthocyanins in Negrinha do Freixo (sample N1) and Picual (sample O1) can be explained by the fact that the fruits of these cultivars are usually consumed as naturally black table olives, which means that they are collected when almost black (the other cultivars are usually used for oil production and are collected before they reach complete maturation).
Q10. What is the M.I. of the sample B1?
For instance sample B1, with a M.I. of 3.3, presented higher amounts of anthocyanins than many other samples with higher M.I., leading to the assumption that factors other than ripeness influence the anthocyanin content.
Q11. What is the luteolin content in olives?
Although it is generally accepted that free flavonoids appear at the end of the maturation stage as a consequence of hydrolytic processes, no correlation was found between maturation index and the levels of free luteolin.
Q12. How many ml/min was the injection volume for the analysis?
Chromatographic separation was carried out as reported previously (Vinha et al., 2002), with an analytical HPLC unit (Gilson), using a Spherisorb ODS2 column (250 · 4.6 mm, RP-18, 5 lm particle size, Merck, Darmstadt, Germany) with the solvent system water– formic acid (19:1) (A) and methanol (B), starting with 5% methanol and installing a gradient to obtain 15% B at 3 min, 25% B at 13 min, 30% B at 25 min, 35% B at 35 min, 40% B at 39 min, 45% B at 42 min, 45% B at 45 min, 47% B at 50 min, 48% B at 60 min, 50% B at 64 min and 100% B at 66 min.