Volatile compounds in the thermoplastic extrusion of bovine rumen

Abstract

Recebido em 1/11/07; aceito em 12/6/08; publicado na web em 5/11/08The volatile compounds of raw and extruded bovine rumen, extracted by dynamic headspace, were separated by gas chromatography and analyzed by GC-MS. Raw and extruded materials presented thirty-two volatile compounds. The following compounds were identified in raw bovine rumen: heptane, 1-heptene, 4-methyl-2-pentanone, toluene, hexanal, ethyl butyrate, o-xylene, m-xylene, p-xylene, heptanal, limonene, nonanal, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane and octadecane. The following compounds were identified in the extruded material: 1-heptene, 2,4-dimethylhexane, toluene, limonene, undecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane and nonadecane. Mass spectra of some unidentified compounds indicated the presence of hydrocarbons with branched chains or cyclic structure.Keywords: bovine rumen; extrusion; volatile compounds. introductionSlaughterhouse by-products are parts of animals that are not consumed either for cultural reasons or because they are unappealing to one of the senses. These products have been the targets of attempts at using textural improvement through thermoplastic extrusion. 1Among these by-products, the first stomach of bovines, or bovine rumen, is underused when compared with other meat cuts, although it is used in small scale as tripe stew or "buchada" (a traditional Brazilian dish).Taking into account that rumen represents about 0.6% of the bovine weight, i.e. ca 2.7 kg, 2 and that about 30 million animals were slaughtered in Brazil in 2006, 3 around 81 million kg of nutritionally sound tissue were produced last year.Bovine rumen protein has high digestibility (97%) and can provide all of the essential amino acids recommended by FAO/WHO 4 to preschool children.5 Bovine rumen flour, obtained after its mincing, lyophilization and milling, contains 85% of protein and 17% of lipid on a dry basis. 6 One way to use the bovine rumen is through thermoplastic extrusion, provided it is previously defatted to produce enough barrel resistance in the process. The extrusion is a feasible process used to add value to products by texturizing proteins that would not be used in human nutrition otherwise. The process of extrusion employs high temperature and shear rate for a short time, and yields textured and expanded products such as breakfast cereals, snacks, textured vegetable proteins, pet foods, pasta, and confectionery: toffee, chewing gum, wine gums and jellies, taffy, hard candy and caramels, licorice and chocolate. [7][8][9][10] Rumen protein after extrusion can be used as a food ingredient, adding value to a series of comminuted products, especially meat products. Acceptability of this potential ingredient is dependant on several factors like texture, color and aroma.It is known that aroma is affected by any heat processing such as extrusion with carbohydrates, proteins, lipids and water acting as aroma precursors.11 Caramelization, Maillard reaction, oxidation, degradation, fragment...

Detection of Volatile Organic Compounds in Brucella abortus-Seropositive Bison

“…Further systematic studies are required to confirm the trends that were observed in this pilot study and to clarify their biochemical origin. Heptanal could be of endogenous origin, since it has been found in the headspace of bison muscle, bovine milk, and in raw and extruded bovine rumen . Octanal and acetophenone have been previously observed in bovine breath samples by others, 2-ethyl-1-hexanol have been detected in cattle rumen headspace, and benzaldehyde have been known to be present in dairy cows and/or their waste, consequently any of those materials could have metabolic relevance.…”

“…Heptanal could be of endogenous origin, since it has been found in the headspace of bison muscle, 1 bovine milk, 29 and in raw and extruded bovine rumen. 30 Octanal and acetophenone have been previously observed in bovine breath samples by others, 31 2-ethyl-1-hexanol have been detected in cattle rumen headspace, 32 and benzaldehyde have been known to be present in dairy cows and/or their waste, 33 consequently any of those materials could have metabolic relevance. Although these compounds cannot be attributed to a specific host/agent activity or response, the observed differences in the concentrations of the five statistically significant VOCs may reflect changes in VOC production related to the infection process.…”

The effects of extrusion conditions and the addition of volatile compounds and flavour enhancers to corn grits on the retention of the volatile compounds and texture of the extrudates

“…The volatile compounds were recovered by adsorption on Porapak Q polymer (80–100 mesh, Varian, Lake Forest, USA) by the technique of dynamic headspace, in accordance with the methodology described by Franco & Rodriguez‐Amaya (1983) and adapted by Silva et al. (2008).…”

Sifat Kimia Selai Buah Naga, Komposisi Mikroflora Dan Profil Scfa Feses Relawan

“…b ) Sebanyak 0,1 g feses manusia sehat ditera dengan larutan garam fisiologis dan dihomogenkan dengan menggunakan vortex selama 10 detik. (Silva et al, 2008;Nurhayati, 2011). Sebanyak 1 mL cairan feses (10% b/v) dimasukkan ke dalam tabung eppendorf dan ditambahkan 0,003 g asam sulfo 5-salisilat dihidrat (Merck, Jerman).…”