Search

Carrot and parsnip slices were subjected to hot drying at 50, 60 and 70 °C with or without pulsed electric field (PEF) pre-treatment at 0.9 kV/cm and 1000 and 10,000 pulses. The effect of drying on processed samples was assessed by analysis of carotenoids, the furosine value, total phenols and the Whiteness Index (WI). PEF pre-treatment is effective in reducing drying times, but the degree of cellular breakdown makes the compounds more susceptible to chemical and enzymatic reactions. In our condition PEF pre-treatment increased the carotenoid degradation and promoted the Maillard reaction above all at the highest temperature of 70 °C. The assessment of carotenoid stability, together with the furosine value, were confirmed to be useful tools for the evaluation of effects of thermal damage and quality of dried food products, also after different drying treatments.

Lipophilic antioxidants are essential components, which have been pointed as bioactive beneficial for human health. This study aimed at evaluating the effect of domestic cooking (boiling, steaming) on the main carotenoids (lutein and β-carotene) and tocols in four different green leafy vegetables: Sonchus asper L. Hill, Sonchus oleraceus L., Spinacia oleracea L. and Cichorium intybus L. The total content of the analyzed compounds was determined following the method of alkaline hydrolysis of the matrix and solvent extraction. The leaching of soluble solids after domestic cooking was found to determine a gain in the investigated bioactive compounds in the cooked vegetables, so to cause an apparent content increase in all leafy vegetables, when expressed as mg/100 g dry matter. Considering solid losses, all lipophilic compounds were not affected by boiling, on the contrary, steaming slightly significantly decreased the contents of lutein and β-carotene (on average 20 and 15%, respectively).

The aim of this research was to study the evolution of carotenoid compounds, antioxidant &beta, ctivity, volatiles and sensory quality in two mango cultivars dried at 50, 60 and 70 &deg, C. Total carotenoids in fresh samples were about 12 and 6 mg/100 g (dry basis) in Keitt and Osteen samples, respectively. &beta, carotene was the main carotenoid, representing about 50% of total carotenoids. In both cultivars, carotenoids were more susceptible to drying at 60 &deg, C. Total phenols and metal reduction activity were higher in Osteen than in Keitt, which had higher values in radical scavenging capacity. The antioxidant activities were best preserved with drying temperatures at 50 &deg, C in Keitt and 60 &deg, C in Osteen fruits. Fresh Osteen mango fruits had a volatile compound content of about 37.1, while Keitt of about 5.2 mg/kg (dry basis). All the compounds with odorous impact were significantly reduced after drying. As regards organoleptic characteristics through sensory analysis, Keitt dried mangoes were quite similar to the fresh product, compared to Osteen.

Three wild edible plant species belonging to the Asteraceae family, Crepis vesicaria L. (s.l.), Sonchus asper (L.) Hill s.l., and Sonchus oleraceus L., usually consumed in the Mediterranean diet, were tested for their nutritional composition and content of carotenoids, tocols, thiamine and riboflavin. Low amounts of thiamine and riboflavin were found. All species were sources of xanthophylls (violaxanthin, neoxanthin, lutein, zeaxanthin and β-cryptoxanthin) and carotenes (α-carotene, β-carotene, 9-cis-β-carotene and 13-cis-β-carotene). Lutein accounted for the highest content (about 4mg/100g). They had good tocol amounts, in particularα-tocopherol (about 2–3mg/100g). Taking into account the Recommended Daily Allowance (RDA) established by the EU Regulation, the analyzed plants can be declared as a source of fiber, vitamin A and E. These data could be useful for database on the nutritional and bioactive compound profile of studied plants and can contribute in promoting their use in functional foods.

Interest in gluten-free grains is increasing, together with major incidences of celiac disease in the last years. Since to date, knowledge of the nutritional and bioactive compounds profile of alternative gluten-free grains is limited, we evaluated the content of water-soluble (thiamine and riboflavin) and liposoluble vitamins, such as carotenoids and tocols (tocopherols and tocotrienols), of gluten-free minor cereals and also of pseudocereals. The analysed samples showed a high content of bioactive compounds, in particular, amaranth, ca&ntilde, ihua and quinoa are good sources of vitamin E, while millet, sorghum and teff (Eragrostis tef, or William&rsquo, s Lovegrass) are good sources of thiamine. Moreover, millet provides a fair amount of carotenoids, and in particular of lutein. These data can provide more information on bioactive compounds in gluten-free grains. The use of these grains can improve the nutritional quality of gluten-free cereal-based products, and could avoid the monotony of the celiac diet.

The aim of this study was to fully characterize the main pigmented rice varieties, available to consumers on the Italian market, in terms of carotenoids, total phenolic compounds and anthocyanins, and to investigate the effect of cooking on these components. Lutein was the main carotenoid in all samples under investigation (0.33-4.11 µg/g d.m.), while anthocyanins were observed only in black genotypes. Phenolic compounds were found mainly in free form, and values ranged between 544.1 and 1508.3 mg/100 g (d.m.) in raw samples. Cooking decreased significantly (p 0.05) total lutein, free phenolic compound and anthocyanin content. In contrast, the increase of insoluble-bound phenolic compounds was observed in some samples, after cooking. The study provides data contributing to gain a better knowledge in novel food composition and enabling the estimation of dietary intake of health-promoting components.

The kinetics of carotenoid and color degradation, as well as furosine formation, were investigated in apricot fruits during convective heating at 50, 60 and 70 °C. Degradation of carotenoids and color, expressed as total color difference (TCD), followed a first and zero order kinetic, respectively. The activation energy (Ea) for carotenoids degradation ranged from 73.7 kJ/mol for 13- cis -β-carotene to 120.7 kJ/mol for lutein, being about 91 kJ/mol for all- trans -β-carotene. Violaxanthin and anteraxanthin were the most susceptible to thermal treatment. The furosine evolution was fitted at zero order kinetic model. The Ea for furosine formation was found to be 83.3 kJ/mol and the Q 10 (temperature coefficient) varied from 1.59 to 4.14 at the temperature ranges 50–60 °C and 60–70 °C, respectively.

Lipophilic antioxidants are essential components of plant defense against stressful conditions. The response of carotenoids and tocols to water deficit and sulfur fertilization was investigated in durum wheat cultivars. The amounts of tocols and carotenoids were evaluated in both whole meal and semolina samples. Differences among cultivars were observed. Simeto cultivar showed a significant effect of water regime on whole meal and semolina carotenoids, with about 20% and 15% increase, respectively. Also tocols and tocotrienols of Simeto were positively affected by water stress (about 10% increase and 15% increase in whole meals and semolinas). Sulfur fertilization positively impacted mainly Ofanto whole-grain and semolina carotenoids, semolina tocols, and tocotrienols. In conclusion, water deficit occurring under a Mediterranean environment was responsible for an improvement of lipophilic antioxidant content in durum wheat; in contrast sulfur supplementation did not improve the response of the antioxidant pool under water deficit.

A simple and rapid analytical method for the determination of lutein content, successfully used for cereal matrices, was evaluated in fruit and vegetables. The method involved the determination of lutein after an alkaline hydrolysis of the sample matrix, followed by extraction with solvents and analysis by normal phase HPLC. The optimized method was simple, precise, and accurate and it was characterized by few steps that could prevent loss of lutein and its degradation. The optimized method was used to evaluate the lutein amounts in several fruit and vegetables. Rich sources of lutein were confirmed to be green vegetables such as parsley, spinach, chicory, chard, broccoli, courgette, and peas, even if in a range of variability. Taking into account the suggested reference values these vegetables can be stated as good sources of lutein.

This chapter reports the ‘state of the art’ of the influence of the pasta-making process on tocols, carotenoids, and retinols. Available literature reveals that processing may influence the levels of these compounds in the final products, depending on several physical and chemical factors, such as light, temperature, pH, O2, food composition, presence of antioxidants, and the different extent of lipoxygenase activity in the kernel. During the pasta making process the degradation of tocols and carotenoids is mostly limited to the kneading step, where several physical-chemical and enzymatic factors seem to exert an important role in determining their degradation, while significant losses during drying treatments are observed only at high temperatures. An increase in geometric isomerization from the trans to the cis forms of carotenoids and retinols is also reported. The pasta-making process does not seem to influence the bioaccessibility of tocols and carotenoids from durum wheat pasta. The use of a suitable procedure for the extraction and determination of carotenoids, tocols, and retinols from cereal matrices is also discussed.

"Carotenoids are natural compounds whose nutritional importance comes from the provitamin A activity of some of them and their protection against several serious human disorders. The degradation of carotenoids was investigated during apricot drying by microwave and convective hot-air at 60 and 70 A degrees C. Seven carotenoids were identified: antheraxanthin, lutein, zeaxanthin, beta-cryptoxanthin, 13-cis-beta-carotene, all-trans-beta-carotene and 9-cis-beta-carotene; among these, all-trans-beta-carotene was found to be about 50 % of total carotenoids. First-order kinetic models were found to better describe all-trans-beta-carotene reduction during drying, with a degradation rate constant (k(1)) that increased two folds when temperatures increased by 10 A degrees C, in both methods. No differences were found in k(1) between apricots dried by hot air at 70 A degrees C (k(1) = 0.0340 h(-1)) and by microwave at 60 A degrees C. The evolution of total carotenoids (117.1 mg\/kg on dry basis) during drying highlighted a wider decrease (about 50 %) when microwave heating was employed, for both set temperatures. Antheraxantin was found to be the carotenoid most susceptible to heat, disappearing at 6 h during both trials with microwave as well as during convective hot-air at 70 A degrees C. For this reason, antheraxanthin could be a useful marker for the evaluation of thermal damage due to the drying process. Also the degree of isomerization of all-trans-beta-carotene could be a useful marker for the evaluation of the drying process."

Color is an important parameter involved in the definition of semolina and pasta quality. This character is mainly due to natural pigments (carotenoids) that are present at different levels in cereals and cereal products, due to botanical origin, growing conditions, distribution in the kernel, and technological processes. In food industries, color measurements are usually performed by means of automatic instruments that are rapid and safe, as alternatives to the chemical extraction methods. In this study, automatic measurements (CIE, color-space system L, a, b), water-saturated butanol (WSB), and HPLC determinations have been applied to evaluate the carotenoid content in whole meals and respective semolina samples produced from wheat cultivated in the years 2001 and 2002. In whole meals, total carotenoids, determined by HPLC, were about 3.0 microg/g (2001) and 3.5 microg/g (2002) calculated on dry weight (dw) and about 3.0 and 3.2 microg/g dw in corresponding semolina samples. The b values for the same period were 19.78 and 15.75, respectively, in raw materials and 20.03-21.67 in semolina. Results have confirmed lutein and beta-carotene as the main components mainly responsible for the yellow color in wheat grains. The ability of the index b to express natural dyeing was dependent on sample characteristics as demonstrated by the relationships found between this index and pigments, although the best correlation resulted between HPLC and WSB.