Dietary inclusion of tomato pomace improves meat oxidative stability of young pigs.

The aim of this study was to assess the nutritional effect of tomato pomace, in combination with two distinct fat sources (lard or soya bean oil), on longissimus lumborum muscle, subcutaneous fat and liver of young pigs. Forty male pigs of 4 weeks old were randomly assigned to four dietary treatments using two fibre sources (wheat bran or 5.0% tomato pomace) and two fat sources (lard or soya bean oil), in a 2 × 2 factorial design for a 5-week trial. Tomato pomace did not improve colour, fatty acid profile, cholesterol content or lipid oxidation, nor did it yield detectable levels in lycopene or ß-carotene in the meat (p > 0.05). However, a positive increase in α-tocopherol content of meat and liver was observed in pigs fed tomato pomace (p < 0.05). Compared with lard, soya bean oil increased MUFA and PUFA proportions and decreased the percentage of SFA (p < 0.05). Our results indicate that 5.0% of tomato pomace increases pork oxidative stability and that 5.0% of soya bean oil, compared with lard, improves its nutritional quality.

Preliminary results on the effects of grape (Vitis vinifera) seed condensed tannins on in vitro intestinal digestibility of the lupin (Lupinus angustifolius) seed protein fraction in small ruminants.

Condensed tannins (CT) from grape seeds (Vitis vinifera L.) were added to complex the protein fraction of Lupinus angustifolius seeds. Three CT/protein ratios were used: 96 mg/g (T(1)), 180 mg/g (T(2)) and 0 mg/g (T(0)). The CP losses in the rumen were assessed by the nylon-bag technique and CP intestinal digestibility (CPID) was estimated using an in vitro assay applying a three-step procedure: samples were subject to rumen degradation (in situ, 16 h) and the remaining residues were subject to the digestive enzymes of the abomasum and pancreas in vitro. A positive effect (p < 0.05) of the level of CT on the immediately soluble faction a and the insoluble degradable fraction b was observed between T(0) and T(2) . In the presence of CT the rumen degradation rate was reduced (p < 0.05) from 0.0763/h (T(0)) to 0.0443/h (T(2)). The application of CT showed a reduction (around 10% for T(1)) of effective rumen CP degradability. The CPID did not seem to be affected (p > 0.05) by the presence of CT. These findings suggest that the use of grape seed CT might have the potential to improve the efficiency of utilisation of the protein fraction from lupin seeds.

Growth inhibition of bacterial isolates recovered from two types of Portuguese dry smoked sausages (chouriço).

Potassium sorbate (PS), sodium benzoate (SB) and methyl p-hydroxybenzoate (MHB) were investigated as surface treatments for their ability to inhibit the growth of 18 isolates of spoilage and pathogenic bacteria from two types of Portuguese dry smoked sausages (Chouriço). MHB significantly inhibited the growth rate of 12 of the isolates (p<0.05) whereas no effect was observed for four isolates of lactic acid bacteria, identified as Enterococcusfaecium, Pediococcusacidilactici and Lactobacilluscurvatus, and two isolates identified as Clostridiumaminovalericum and Staphylococcusepidermidis. PS and SB had less influence on the bacterial growth rates. It was concluded that MHB can be applied as surface treatment to improve the stability and safety of the product along shelf life period in modified atmosphere package.

Mycoflora of two types of Portuguese dry-smoked sausages and inhibitory effect of sodium benzoate, potassium sorbate, and methyl p-hydroxybenzoate on mold growth rate.

The mycoflora of chouriqo types Alentejano and Ribatejano, two varieties of Portuguese dry-smoked sausages, have been investigated after a producer-defined shelf life period (120 days at 20 +/- 5 degrees C) in modified atmosphere packaging (55% N2 and 45% CO2). On the basis of morphological and physiological characteristics, the isolates were identified as Penicillium, Aspergillus, Fusarium, Rhizopus, Monilia, Absidia, and Cephalosporium. The species identified were as follows: Penicillium terrestres (43.4%), Penicillium sp. (13.3%), Fusarium sp. (10%), Aspergillus glaucus (10%), Aspergillus versicolor (6.8%), Monilia fruticola (3.3%), Absidia sp. (3.3%), Cephalosporium sp. (3.3%), Rhizopus stolonifer (3.3%), and Fusarium tricinctum (3.3%). Additionally, the effects of three preservatives (potassium sorbate [PS], sodium benzoate [SB], and methyl p-hydroxybenzoate [MHB]) were studied on the growth rate of mold representative isolates. MHB showed a greater inhibitory effect than SB and PS in all fungi isolates, except in A. glaucus [Tm30(A)], in which the inhibitory effect of MHB was similar to PS. At 0.05% (wt/vol), all fungi were inhibited with MHB, except for R. stolonifer [Tm25(A)], which started to decrease the growth rate only at a concentration higher than 0.1%. PS was more effective at inhibiting mold growth than SB, except in Absidia sp. [Tm16(R)], in which both showed a similar inhibitory effect. MHB showed great promise as an application to the surface at 0.1% (wt/vol) to improve the stability and safety of the product through the inhibition of potential spoilage and toxigenic molds.

Effect of packaging technology on microbiological and sensory quality of a cooked blood sausage, Morcela de Arroz, from Monchique region of Portugal.

Morcela de Arroz (MA), a popular Portuguese blood sausage, with high pH and water activity (aw), is traditionally commercialized without preservatives and unpacked. This study evaluated the best packaging solution to extend MA shelf life stored at 4±1°C for 44days: without packaging (WP), vacuum (VP) and modified atmosphere packaging (MAP) (80% CO2; 20% N2). Mesophilic (MTVC), psychrotrophic (PTVC), lactic acid bacteria (LAB), pseudomonads, molds and yeasts, Enterobacteriaceae, Listeria monocytogenes, Salmonella spp., Bacillus cereus, Clostridium perfringens, sensory properties, pH, moisture and aw were studied. Moisture and aw decreased (p<0.05) in WP. pH decreased in WP and MAP during storage. MTVC and PTVC counts increased to values around 7logCFU/g at 44days of storage. LAB and Enterobacteriaceae counts were higher (p<0.05) in VP. Pseudomonads were inhibited (p<0.05) by MAP after 8days of storage. Sensory parameters were affected (p<0.05) by packaging and storage time. Globally, MAP performed better.