GC-MS analysis of D-pinitol in carob: Syrup and fruit (flesh and seed).

D-pinitol (3-O-methyl-D-chiro-inositol) is a well-known bioactive compound with anti-diabetic and anti-oxidant biological functions. A gas chromatography-mass spectrometry (GC-MS) method was developed for its quantitation in carob syrup, flesh and seed samples originated from Cyprus. The analysis was performed after derivatization of carbohydrates and polyols into trimethylsilyl ether derivatives. D-pinitol was determined in 13 carob syrup samples, in concentrations ranging 65.71 ± 4.60 - 77.72 ± 5.44 mg/g (mean: 68.58 ± 4.80 mg/g, n = 13). In two commercial samples, it was determined in relative medium-low concentrations (21.96 ± 1.54 and 44.71 ± 3.13 mg/g), revealing possible adulteration; however, this needs further investigation. Similarly, it was determined in high concentrations in carob flesh samples, in concentrations ranging 53.20 ± 3.72 - 54.58 ± 3.82 mg/g (mean: 53.81 ± 3.76 mg/g, n = 3). On the other hand, seed samples proved very poor in D-pinitol (<LOD). Therefore, bioprospecting of carob fruit and syrup is highlighted. Compared to other plants or legumes, carob appears to be the richest source of D-pinitol, highlighting carobs role as a functional organic food. The historical and cultural association of Cyprus with carobs is linked with traditional foods and habits.
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