• Mixing sweet cream buttermilk with whole milk to produce cream cheese

      Bahrami, Masoud; Ahmadi, Dariush; Beigmohammad, Faranak; Hosseini, Fakhrisadat (Teagasc (Agriculture and Food Development Authority), Ireland, 2015-12-30)
      Buttermilk is an important by-product of the manufacture of butter. Sweet-cream buttermilk (SCBM) is similar in composition to skim milk, except for its high phospholipid and milk fat globular membrane protein content. The main objective of this investigation was to produce optimum quality cream cheese by replacing whole milk with different proportions of SCBM (5, 10, 15, 20, 25, 30, 35, 40, 45, and 50%). Statistical analysis showed that there were significant differences (p < 0.05) between the chemical and organoleptic properties of the samples. As the percentage of SCBM increased, the chemical composition of total solids, fat, protein, fat in dry matter (FDM) and ash of cheese milk decreased significantly, leading to a softer, moister curd. Samples prepared with more than 25% SCBM were not acceptable to the taste panel. The cream cheeses prepared using 25% and 30% SCBM had the highest yields. Total solids and FDM were strong predictors of cheese yield (r2 ≈ 0.589). The results also showed that the best range for replacement using SCBM is 20–25%.
    • Mycotoxin occurrence on baled and pit silages collected in Co. Meath

      McElhinney, Cormac K.; Danaher, Martin; Elliott, C.; O'Kiely, Padraig (Teagasc (Agriculture and Food Development Authority), Ireland, 2015-12-30)
      Recent studies of baled silages produced in Ireland have identified considerable filamentous fungal contamination. Many of these fungi are toxigenic, capable of producing secondary metabolites, namely mycotoxins. Mycotoxins are potentially detrimental to livestock health and some can pose a risk to consumers of animal products. Baled (n=20) and pit (n=18) silages from a sample of farms (n=38) in Co. Meath were examined to assess the occurrence of mycotoxins and ascertain whether sampling position within the pit silos (feed face vs. 3 m behind the feed face) has an effect on mycotoxin content or other chemical compositional variables. Of the 20 mycotoxins assayed, baled silages contained [mean of positive values (no. of values in mean)] mycotoxin concentrations (μg/kg dry matter) of beauvericin 36 (2), enniatin (enn.) A 9.3 (3), enn. A1 54 (8), enn. B 351 (9), enn. B1 136 (10), mycophenolic acid (MPA) 11,157 (8) and roquefortine C (Roq. C) 1037 (8) and pit silages contained beauvericin 25 (2) enn. A1 18 (2), enn. B 194 (9), enn. B1 57 (3), MPA 287 (6), Roq. C 3649 (6) and zearalenone 76 (1). There was no difference (P>0.05) observed in the mycotoxin concentrations between baled and pit silages, and 11 of the 20 mycotoxins assayed were below the limits of detection. The position of sampling had no effect on the mycotoxin concentration detected in pit silages. It is concluded that mycotoxin concentrations detected in these pit and baled silages in Co. Meath did not exceed EU regulation or guidance limits, and that similar chemical composition and mycotoxin concentration values occurred at the pit silage feed face and 3 m behind this feed face.
    • A note on challenge trials to determine the growth of Listeria monocytogenes on mushrooms (Agaricus bisporus)

      Leong, Dara; Alvarez-Ordonez, Avelino; Jordan, Kieran; Safefood (Teagasc (Agriculture and Food Development Authority), Ireland, 30/12/2015)
      In the EU, food is considered safe with regard to Listeria monocytogenes if the number of micro-organisms does not exceed 100 colony forming units (cfu)/g throughout its shelf-life. Therefore, it is important to determine if a food supports growth of L. monocytogenes. Guidelines for conducting challenge tests for growth assessment of L. monocytogenes on foods were published by the European Union Reference Laboratory (EURL) in 2014. The aim of this study was to use these guidelines to determine if refrigerated, fresh, whole, closed-cap, prepackaged mushrooms (Agaricus bisporus) support the growth of L. monocytogenes. Three batches of mushrooms were artificially inoculated at approximately 100 cfu/g with a three-strain mix of L. monocytogenes and incubated for 2 days at 8°C followed by 4 days at 12°C. L. monocytogenes numbers were determined (in triplicate for each batch) on days 0, 2 and 6. Water activity, pH and total bacterial counts were also determined. There was no increase in the number of L. monocytogenes above the threshold of 0.5 log cfu/g in any of the replicates. In 8 of 9 replicates, the numbers decreased indicating that A. bisporus do not support the growth of L. monocytogenes. As the EU regulations allow < 100 cfu/g if the food cannot support growth of L. monocytogenes, the significance of this study is that mushrooms with < 100 cfu/g may be within the regulations and therefore, quantitative rather than qualitative determination may be required.
    • A note on the Hybrid Soil Moisture Deficit Model v2.0

      Schulte, Rogier P.; Simo, Iolanda; Creamer, Rachel E.; Holden, Nicholas M. (Teagasc (Agriculture and Food Development Authority), Ireland, 30/12/2015)
      The Hybrid Soil Moisture Deficit (HSMD) model has been used for a wide range of applications, including modelling of grassland productivity and utilisation, assessment of agricultural management opportunities such as slurry spreading, predicting nutrient emissions to the environment and risks of pathogen transfer to water. In the decade since its publication, various ad hoc modifications have been developed and the recent publication of the Irish Soil Information System has facilitated improved assessment of the spatial soil moisture dynamics. In this short note, we formally present a new version of the model (HSMD2.0), which includes two new soil drainage classes, as well as an optional module to account for the topographic wetness index at any location. In addition, we present a new Indicative Soil Drainage Map for Ireland, based on the Irish Soil Classification system, developed as part of the Irish Soil Information System.
    • The response of sward-dwelling arthropod communities to reduced grassland management intensity in pastures

      Helden, Alvin J.; Anderson, Annette; Finn, John; Purvis, Gordon (Teagasc (Agriculture and Food Development Authority), Ireland, 2015-12-30)
      We compared arthropod taxon richness, diversity and community structure of two replicated grassland husbandry experiments to investigate effects of reduced management intensity, as measured by nutrient input levels (390, 224 and 0 kg/ha per year N in one experiment, and 225 and 88 kg/ha per year N in another). Suction sampling was used to collect Araneae, Coleoptera, Hemiptera and Hymenoptera, with Araneae and Coleoptera also sampled with pitfall trapping. Univariate analyses found no significant differences in abundance and species density between treatments. However, with multivariate analysis, there were significant differences in arthropod community structure between treatments in both experiments. Reducing N input and associated stocking rates, as targeted by agri-environment schemes, can significantly alter arthropod communities but without increasing the number of species present. Other approaches that may be necessary to achieve substantial enhancement of sward arthropod biodiversity are suggested.