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The amino acid profile of 11 samples of tiger nuts ( Cyperus esculentusL.) grown in the area of “L'Horta Nord” in Valencia (Spain) and one sample of African origin were determined, along with the amino acid contents of 10 samples of natural orgeat from Valencia. Protein was hydrolysed by hydrochloric acid at 110 °C for 23 h, and amino acids were derivatised with AQC and determined by RP-HPLC with fluorescence detection. The chromatographic conditions were optimised. The analytical parameters (detection and quantification limits, precision and accuracy) showed the method to be sufficiently sensitive and reproducible for determining amino acids resistant to acid hydrolysis in tiger nuts and orgeat. Arginine was the most abundant amino acid in both tiger nuts and orgeat and the lowest contents corresponding to histidine and tyrosine. The essential amino acid contents of tiger nuts and orgeat protein were greater than those proposed in the protein standard for adults by the FAO/WHO, with the exception of histidine. No significant differences were found among the arginine, lysine and isoleucine amino acid contents in tiger nuts from Valencia, Alboraya and Alm‡ssera; nor were they found among amino acids in tiger nuts from Valencia and Alm‡ssera, with the exception of tyrosine.

The effect of storage during 9 months at 25º, 30º and 37ºC on furosine formation in three milk-cereal based baby foods was studied to evaluate development of the Maillard reaction. Furosine was measured by HPLC-UV. Immediately after the manufacturing process, furosine contents were 310-340 mg/100 g protein and at the 9 th storage month were 426-603 mg/100 g protein. Storage time and temperature have a significant increase (p0.05) of furosine content during storage. Furosine contents were higher in sample containing honey than in those without honey. Interactions (p0.05) between storage time and temperature or type of sample were found. A predictive model equation of the evolution of furosine during storage explaining 80% of the variability in furosine content was obtained. The blockage of lysine through storage calculated using the furosine and total lysine provided values ranged from 9.5 to 18.1 % for analysed baby foods.