Maria Regina Bueno Franco

Aroma volatiles recovered in the water phase of cashew apple (Anacardium occidentale L.) juice during concentration

BACKGROUND There is a considerable loss of volatile compounds during the thermal concentration of cashew apple juice, damaging product quality, and as yet there is little research on the subject. Thus the purpose of this research was to identify the aroma volatiles evaporated off from cashew apple juice and recovered in the water phase during concentration of this beverage in an industrial plant. Water phase volatiles were extracted using dichloromethane, concentrated under a nitrogen flow, separated by gas chromatography (GC) and identified by GC-mass spectrometry. In order to determine the contribution of each volatile to the cashew aroma, five trained judges evaluated the GC effluents using the Osme GC-olfactometry technique. RESULTS 71 volatiles were identified; of these, 47 were odour active. Alcohols were preferentially recovered in the cashew water phase, notably heptanol, trans-3-hexen-1-ol and 3-methyl-1-butanol, representing 42% of the total chromatogram area and imparting green grass and fruity aroma notes to the water phase. Esters represented 21% of the total chromatogram area, especially ethyl 2-hydroxyhexanoate, ethyl trans-2-butenoate and ethyl 2-methylbutanoate, and were responsible for the fruity/cashew-like aroma of the water phase. On the other hand, 3-methylbutanoic and 2-methylbutanoic acids were the volatiles that presented the greatest odour impact in the GC effluents of the water phase. CONCLUSION Overall, the results of the present study strongly indicated that further concentration of the esters recovered in the water phase, either by partial distillation or by alternative technologies such as pervaporation, could generate a higher-quality natural cashew apple essence.

Fatty acid composition of total lipids, neutral lipids and phospholipids in wild and farmed matrinxã (Brycon cephalus) in the Brazilian Amazon area

BACKGROUND The chemical composition of Amazonian fish is extremely variable, being influenced by the season and the type and amount of food. A special interest in the fish oil composition has been developed owing to the presence of essential fatty acids, since this is directly related to human health. This study aimed to investigate the fatty acid composition (FAC) of the total lipid (TL), neutral lipid (NL) and phospholipid (PL) fractions of the dorsal muscle and orbital cavity of farmed and wild matrinxã in the Amazon area captured in different seasons. RESULTS Fatty acids (FA) were analysed by high-resolution gas chromatography/mass spectrometry. Sixty-five FA were detected in the TL, 66 in the NL and 55 in the PL. The main FA found in farmed and wild fish were oleic, palmitic, stearic and linoleic acids. No distinctions in the quality or quantity of these fractions between dorsal muscle and orbital cavity were found. CONCLUSION The season had a significant influence on the TL and FAC. Fish captured during the dry season showed lower levels of lipid and a higher percentage of long-chain polyunsaturated fatty acids. Matrinxã farmed in a semi-intensive system showed a nutritional quality comparable to that of wild matrinxã captured in the wet season. Copyright

Compostos voláteis de três cultivares de manga (Mangifera indica L.)

The volatile compounds of three mango cultivars (Haden, Tommy-Atkins and Keitt), from the State of Sao Paulo, were isolated by a dynamic headspace technique involving suction on a porous polymer. The complex mixture of volatile compounds was separated by high-resolution gas chromatography. Some volatiles were identified by gas chromatography-mass spectrometry and Kovats Indices. The monoterpene hydrocarbons were the most abundant in the headspace of the fruits. Car-3-ene was the major component of the cultivars Haden and Keitt, while the Tommy Atkins mango exhibited predominance of two constituents, car-3-ene and a-pinene. Other identified compounds were a-fenchene, a-camphene, p-cimene, b-mircene, b-phellandrene, limonene, a-terpinolene, b-caryophyllene e a-humulene. Samples of the same cultivar demonstrated great homogeneity, with no statistically significant difference being observed among the three lots analyzed for each cultivar.

Relação entre teores de colesterol em filés de tilápias e níveis de óleo de linhaça na ração

The objective of this study was to investigate the effect of fish feed containing different levels of linseed oil on the cholesterol content and proximate composition (moisture, ash, protein and total lipids) of tilapia fillets. The cholesterol content was determined using high performance liquid chromatography (HPLC), the methodology being evaluated and validated and shown to be exact and precise. The cholesterol contents varied from 58 to 76mg/100g of muscle tissue, the inclusion of linseed oil up to a level of 3.75% favoring a decrease in the cholesterol content of the tilapia fillets, although the levels continued to be similar to those of other fish. There was no significant difference between the treatments with respect to the proximate composition. Thus the use of linseed oil presented no influence on the composition of the constituents analyzed.

Determinação do perfil de compostos voláteis e avaliação do sabor e aroma de bebidas produzidas a partir da erva-mate (Ilex paraguariensis)

Volatile compounds from green and roasted yerba mate were analyzed by gas chromatography/mass spectrometry and the flavor profile from yerba mate beverages was determined by descriptive quantitative analyses. The main compounds tentatively identified in green mate were linalool, a-terpineol and trans-linalool oxide and in roasted mate were (E,Z)-2,4-heptadienal isomers and 5-methylfurfural. Green mate infusion was qualified as having bitter taste and aroma as well as green grass aroma while roasted mate was defined as having a smooth, slightly burnt aroma. The relationship between the tentatively identified compounds and flavor must be determined by olfatometric analysis.

The influence of fermentation temperature and sulfur dioxide on the volatile composition and flavour profile of cashew wine

Fresh cashew juice was inoculated with Saccharomyces bayannus and fermented at 18 and 30°C. Sulfur dioxide was added at 0, 50, 100 and 200 mg/kg. The headspace volatiles were identified by gas chromatography—mass spectrometry and sniffed using the Osme technique. The flavour profiles were generated by Quantitative Descriptive Analysis. Impact volatiles included ethyl esters associated with fruit flavour. A refrigerated fermentation provided better wines, increasing the levels of compounds with cashew, fruity and sweet notes and decreasing undesirable compounds perceived as ‘fermented’, ‘plastic’ and or ‘smelly’. A low level of sulfitation was required to obtain a fruity cashew wine whereas too much sulfite favoured the production of isobutanol and hexanoic acid, which could impair the sensory quality of the product.

Tocoferois do músculo dorsal e cavidade ocular do matrinxã (Brycon cephalus) proveniente da Bacia Amazônica em diferentes épocas sazonais

This research aimed to determine the content of different tocopherol levels in muscle and ocular cavity of matrinxa fishes captured in the Central Amazon Region - Brazil. For the antioxidants determination, three batches, each consisting of 5 fish, during two different seasons. The analyses were performed according to the AOCS Ce 8-89 (1993) methodology in chromatography HPLC PERKIN ELMER - Isocratic LC 250 pump couple to fluorescence detector (SHIMADZU - RF - 10AxL). The a-tocopherol was predominant in the different seasons. The tocopherol content ranged from 0.43 to 0.04mg 100-1 and from 8.2 to 0.06mg 100g-1 in the muscle of matrinxa captured in the flood ad dry season, respectively. The tocopherol content in the adipose tissue of the orbital cavity of matrinxa captured in the flood ad dry season showed ranged from 0.09 a 0.02mg 100g-1 and from 0.42 to 0.03mg 100g-1, respectively.