Rosa Escudero

Effect of fatty acid composition and positional distribution within the triglyceride on selected physical properties of dry-cured ham subcutaneous fat.

Analysis of fatty acid (FA) positional distribution within the triglyceride (TG) and selected physical properties of dry-cured ham subcutaneous fat (SF) were carried out. The slip point (SP) of the SF was related to the concentration and positional distribution of FA. When C16:0 was in Sn-2, the SP depended on the FA present in Sn-1,3. Hardness was related to the FA concentration in external positions of TG. A significant direct linear correlation between hardness against C18:0, SFA and average chain length (ACL) and inverse against C18:1, C18:2 and PUFA and unsaturation index (UI) in external positions was found. Adhesiveness was related to SFA, C16:0, C18:0, C18:1, MUFA, UI and ACL exclusively in Sn-2 position. A different role of FA in Sn-2 and Sn-1,3 positions on SP and texture properties of fat was found.

Synthesis and chemical characterization of the novel agronomically relevant pentadentate chelate 2-(2-((2-hydroxybenzyl)amino)ethylamino)-2-(2-hydroxyphenyl)acetic acid (DCHA).

Iron chelates analogous to o,o-EDDHA/Fe(3+) are the fertilizers chosen to treat iron chlorosis in plants growing on calcareous soil. The isomer o,p-EDDHA/Fe(3+) presents less stability but faster assimilation by the plant than o,o-EDDHA/Fe(3+), because only five coordinating groups are able to complex Fe(3+). The new chelating agent 2-(2-((2-hydroxybenzyl)amino)ethylamino)-2-(2-hydroxyphenyl)acetic acid (DCHA) has been synthesized to obtain an iron fertilizer with intermediate stability between o,o-EDDHA/Fe(3+) and o,p-EDDHA/Fe(3+) and with fast assimilation. Its synthesis has been done starting from phenol, N-acetylethylendiamine, glyoxylic acid, and NaOH in a three-step sequence. The purity of the DCHA chelating agent, its protonation, and Ca(2+), Mg(2+), Fe(3+), and Cu(2+) stability constants, together with its ability to maintain iron in solution in different agronomic conditions, have been determined. The results indicate that the chelate DCHA/Fe(3+) has intermediate stability between those of o,o-EDDHA/Fe(3+) and o,p-EDDHA/Fe(3+) complexes and that it is capable of maintaining the Fe(3+) in agronomic conditions. This new chelating agent may be effective in correcting iron chlorosis in plants.

The suitability of plasma powder for cold-set binding of pork and restructured dry ham

To determine the ability of cold-set binder plasma powder (PP) for manufacturing restructured deboned dry ham, the effect of meat pre-treatment and PP preparation on the binding rate (k) and maximum binding force (BFmax) of pork model systems and deboned ham were evaluated. In pork model systems, the highest values for k (about 0.4Ncm(-2)h(-1)) and BFmax (about 2.5Ncm(-2)) were obtained when powder or rehydrated plasma [in water or in NaCl aqueous solution at 0.5%] was applied onto the meat surface without additional pre-treatment or prior immersion in saline aqueous solution. Similar meat pre-treatment and PP preparation were used to restructure fresh deboned leg resulting in stable meat binding performances during salting and drying. An important increase in the binding force (BFmax>10Ncm(-2)) occurred over the drying period (after 4weeks). Scanning electron microscopy showed different morphologies of the binding area, mainly depending on whether powder or rehydrated plasma was used.

Fertilizer properties of DCHA/Fe3+

AimsThe suitability of the non-symmetrical chelating agent DCHA (2-{2-[(2-hydroxybenzyl)amino]ethylamino}-2-{2-hydroxyphenyl}acetic) to improve Fe nutrition in plants is investigated in order to confirm the good results deriving from its chemical reactivity in agronomic systems achieved by analytical and modeling studies. Moreover, the factors affecting the efficacy of this new Fe chelate, that it is predicted to combine a good stability in nutrient solution and calcareous soils, are explored.MethodsThe role of DCHA/Fe3+ as substrate for the Fe chelate reductase (FCR) activity in cucumber (Cucumis sativus L. cv. Ashley) plants and its efficacy to provide Fe to chlorotic soybean (Glycine max L. cv. Stine 0408) plants in both hydroponic and soil culture were determined.ResultsThe chelate DCHA/Fe3+ presented an intermediate behavior between o,oEDDHA/Fe3+ and o,pEDDHA/Fe3+ as substrate of the FCR. In the hydroponic experiment, nutritional indexes indicated a faster and higher re-greening of the plants treated with DCHA/Fe3+ and o,pEDDHA/Fe3+ than with o,oEDDHA/Fe3+. In the soil experiment, plants treated with o,oEDDHA/57Fe3+ showed the highest 57Fe concentration in leaves and no differences were observed between o,pEDDHA/57Fe3+ and DCHA/57Fe3+.ConclusionsThe chelate DCHA/Fe3+ has adequate fertilizer properties since it is able to correct the Fe chlorosis and to maintain good nutritional status of plants over time both in hydroponic and soil cultures. This is related to its ability to serve as substrate for the FCR and its good stability in solution and in soil conditions observed in this and previous studies.

Electron spin resonance (ESR) spectroscopy study of cheese treated with accelerated electrons

The generation, accumulation and decay of free radicals in six varieties of cheese, irradiated (0-4 kGy) in an electron accelerator, have been studied by electron spin resonance (ESR) spectroscopy. Remarkably, the ESR spectra of all untreated cheeses showed only one singlet signal with a g-factor of 2.0064 ± 0.0005. Surprisingly, the ESR spectra of irradiated samples presented a new signal with g-factor of 2.0037 ± 0.0003 which was independent of the type of cheese, and which might be due to free radicals from the radiolysis of proteins. Surface regression models (P < 0.0001) established the relationship among signal intensity, absorbed dose (0, 1, 2 and 4 kGy) and storage time (0-180 days) for the different types of cheese. Results suggested that the analysis by ESR (or electron paramagnetic resonance, EPR) is suitable to evaluate, either qualitatively or quantitatively, the irradiation treatment of different types of cheese.

Use of MRI as a predictive tool for physicochemical and rheologycal features during cured ham manufacturing

Magnetic resonance imaging (MRI) was used to study the structural changes during dry-cured ham manufacturing. T1, T2 and apparent diffusion coefficient (ADC) were determined. Dry cured hams were analysed at different steps of the manufacturing process (raw, salted, post salted, half-cured and cured). Structural changes were linked with the rheological behaviour, estimated by texture profile analysis (TPA) performed in three different muscles of hams (semimembranosus, semitendinosus and biceps femoris). A decrease for T1, T2 and ADC parameters during the curing process was observed, connected to the dehydration kinetics and salt diffusion. Curing process increased hardness and chewiness and reduced elasticity and cohesiveness. Mathematical models were defined to obtain useful equations to monitor ripening. Multiple and simple linear regression models were performed to predict water and salt content and rheological features evolution through MRI parameters. Best settings were achieved with water and salt content for the three studied muscles (R2 around 0.90). T1, T2 and ADC showed a negative correlation with hardness and a positive relation with springiness and cohesiveness.

Effect of sex and dietary treatment on the composition and rheological properties of dry-cured ham subcutaneous fat

Segura Plaza J.F., Escudero R., Romero de Ávila M.D., Olivares Á., Cambero M.I., López-Bote C.J. (2017): Effect of sex and dietary treatment on the composition and rheological properties of dry-cured ham subcutaneous fat. Czech J. Anim. Sci., 62, 110–120. The effect of sex, dietary fat source (lard vs palm oil), and glycerol inclusion in fattening diet on the composition, fatty acid distribution within the triglyceride (TAG) and slip point and textural parameters was studied on dry-cured hams subcutaneous fat. A marked effect of sex on saturated fatty acids (SFA) percentage was found with barrows showing higher values than gilts. No effect of dietary fat source on subcutaneous SFA or polyunsaturated fatty acids (PUFA) was observed. Dietary glycerol increased monounsaturated fatty acids and decreased total PUFA in subcutaneous fat. Besides, the possibility of altering fatty acid composition at the 2-position of the TAG by dietary intervention during the fattening phase is very limited. Partial restructuration was observed in external positions of the TAG. All these changes affected slip point and textural parameters. An increase of hardness when palm oil was used as dietary fat and a decrease in all textural parameters values when glycerol was included were observed.