Stability of betalain pigments from red beetroot [beta vulgaris]

The crude pigments obtained from red beetroot [Beta vulgaris L.] as root juice were evaluated for their stability at various pH values, different ascorbic acid concentrations, and in the presence of N2, and air. The effect of pasteurisation and storage periods with exposure to light and dark at room temperature and in refrigerator in both the presence and the absence of ascorbic acid as stabilizer was also estimated. The stability of extracted pigments was measured on the basis of their UV-visible absorption spectrum. The stability was found to be strongly dependent on pH values, hence it was the best at pH values between 6.5 and 7. Ascorbic acid at 0.05% was the best concentration to protect the red colour. Both samples treated with ascorbic acid or pasteurisation had much better stability in refrigerator than at room temperature in light or dark after 35 days. The exclusion of light and the presence of N2, improved the stability of beetroot pigments. Beetroot pigments exhibited good stability under selected conditions and these characteristics give them considerable importance to be used in the pharmaceutical and food industries

[Effect of salinity in free proline and betaine contents in Hyoscyamus aureus plants]

Hyoscyamus aureus plants were stressed with three different degrees of salinity in order to study relationships between inorganic ion contents and the contents of betaine and proline, both molecules being considered as plant osmoprotectives. Our results demonstrated that the greater the dry weight average and the [Na[+] + K[+] content and the lower the [Na[+] / Ca2[+] ratio, the higher the proline contents in leaves and roots. Proline accumulation is considered as a response to water deficit and a response against not only Na[+] ions but also K[+] ions accumulation and Ca[2+] ions protector effect. Betaine contents in leaves and roots were not only Na[+] concentration dependent but also depended on macronutrient ionic concentration, and this response showed up with certain lag. We can conclude from our results that in Hyoscyamus aureus plants, betaine accumulation is not a reliable parameter to detect salinity stress, but free proline content increases according to the salinity conditions