• Aroma compound diacetyl suppresses glucagon-like peptide-1 production and secretion in STC-1 cells

      McCarthy, Triona; Bruen, Christine; O'Halloran, Fiona; Schellekens, Harriet; Kilcawley, Kieran; Cryan, John F.; Giblin, Linda; Teagasc Walsh Fellowship Programme; Enterprise Ireland; CC20080001 (Elsevier, 21/01/2017)
      Diacetyl is a volatile flavour compound that has a characteristic buttery aroma and is widely used in the flavour industry. The aroma of a food plays an important role in food palatability and thus intake. This study investigates the effect of diacetyl on the satiety hormone, glucagon-like peptide (GLP-1), using the enteroendocrine cell line, STC-1. Diacetyl decreased proglucagon mRNA and total GLP-1 from glucose stimulated STC-1 cells. This dampening effect on GLP-1 appears to be mediated by increasing intracellular cAMP levels, increasing synthesis of the G protein coupled receptor, GPR120, and its recruitment to the cell surface. Voltage gated Ca2+ channels, K+ATP channels and the α-gustducin taste pathway do not appear to be involved. These findings demonstrate that components contributing to food palatability suppress GLP-1. This ability of diacetyl to reduce satiety signals may contribute to overconsumption of some palatable foods.
    • Assessment of physico-chemical traits related to eating quality of young dairy bull beef at different ageing times using Raman spectroscopy and chemometrics

      Nian, Yingqun; Zhao, Ming; O'Donnell, Colm P.; Downey, Gerard; Kerry, Joseph P.; Allen, Paul; Teagasc Walsh Fellowship Programme (Elsevier, 2017-06-27)
      Raman spectroscopy and chemometrics were investigated for the prediction of eating quality related physico-chemical traits of Holstein-Friesian bull beef. Raman spectra were collected on the 3rd, 7th and 14th days post-mortem. A frequency range of 1300–2800 cm− 1 was used for partial least squares (PLS) modelling. PLS regression (PLSR) models for the prediction of WBSF and cook loss achieved an R2CV of 0.75 with RMSECV of 6.82 N and an R2CV of 0.77 with RMSECV of 0.97%w/w respectively. For the prediction of intramuscular fat, moisture and crude protein content, R2CV values were 0.85, 0.91 and 0.70 with RMSECV of 0.52%w/w, 0.39%w/w and 0.38%w/w respectively. An R2CV of 0.79 was achieved for the prediction of both total collagen and hydroxyproline content, while for collagen solubility the R2CV was 0.88. All samples (100%) from 15- and 19-month old bulls were correctly classified using PLS discriminant analysis (PLS-DA), while 86.7% of samples from different muscles (longissimus thoracis, semitendinosus and gluteus medius) were correctly classified. In general, PLSR models using Raman spectra on the 3rd day post-mortem had better prediction performance than those on the 7th and 14th days. Raman spectroscopy and chemometrics have potential to assess several beef physical and chemical quality traits.
    • Assessment of RNAlater® as a Potential Method to Preserve Bovine Muscle Proteins Compared with Dry Ice in a Proteomic Study

      Zhu, Yao; Mullen, Anne Maria; Rai, Dilip K.; Kelly, Alan L.; Sheehan, David; Cafferky, Jamie; Hamill, Ruth; Teagasc Walsh Fellowship Programme; NFFQ0017 (MDPI, 2019-02-05)
      RNAlater® is regarded as a potential preservation method for proteins, while its effect on bovine muscle proteins has rarely been evaluated. Bovine muscle protein samples (n = 12) collected from three tender (Warner–Bratzler shear force: 30.02–31.74 N) and three tough (Warner–Bratzler shear force: 54.12–66.25 N) Longissimus thoracis et lumborum (LTL) samples, preserved using two different sampling preservation methods (RNAlater® and dry ice), at two post mortem time points (day 0 and day 14), were characterized using one-dimensional electrophoresis. Fourteen bands with molecular weights ranging from 15 to 250 kDa were verified, both in the dry ice and RNAlater® storage groups, at each time point, using image analysis. A shift from high to low molecular weight fragments, between day 0 and day 14, indicated proteolysis of the muscle proteins during post mortem storage. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses and database searching resulted in the identification of 10 proteins in four bands. Protein profiles of muscle preserved in RNAlater® were similar to those of muscle frozen on dry ice storage, both at day 0 and day 14. The results demonstrate that RNAlater® could be a simple and efficient way to preserve bovine muscle proteins for bovine muscle proteomic studies
    • A case of bovine raw milk contamination with Listeria monocytogenes

      Hunt, Karen; Drummond, Niall; Murphy, Mary; Butler, Francis; Buckley, James F.; Jordan, Kieran; Teagasc Walsh Fellowship Programme; Department of Agriculture, Food and the Marine, Ireland; European Union (Biomed Central, 06/07/2012)
      During routine sampling of bulk raw milk on a dairy farm, the pathogenic bacteria Listeria monocytogenes was found to be a contaminant, at numbers < 100 cfu/ml. A strain with an indistinguishable pulsed-field gel electrophoresis pattern was isolated from the bulk milk two months later. Environmental swabs taken at the dairy environment were negative for the presence of L. monocytogenes, indicating a possible case of excretion of the L. monocytogenes directly into the milk. Milk samples were collected from the individual cows and analysed, resulting in the identification of L. monocytogenes excretion (at 280 cfu/ml) from one of the 4 mammary quarters of one dairy cow out of 180. When the infected cow was isolated from the herd, no L. monocytogenes was detected from the remaining herd. The pulsed-field gel electrophoresis pattern of the strain from the individual cow was indistinguishable from that originally isolated from the bulk milk. The infected cow did not show any clinical signs of disease, nor did the appearance of the milk have any physical abnormalities. Antibiotic treatment of the infected mammary quarter was found to be ineffective. This study shows that there can be risks associated with direct contamination of raw milk with L. monocytogenes.
    • Detection of adulteration in fresh and frozen beefburger products by beef offal using mid-infrared ATR spectroscopy and multivariate data analysis

      Zhao, Ming; Downey, Gerard; O'Donnell, Colm P.; Teagasc Walsh Fellowship Programme; Food Safety Authority of Ireland (Elsevier, 17/10/2013)
      A series of authentic and offal-adulterated beefburger samples was produced. Authentic product (36 samples) comprised either only lean meat and fat (higher quality beefburgers) or lean meat, fat, rusk and water (lower quality product). Offal adulterants comprised heart, liver, kidney and lung. Adulterated formulations (46 samples) were produced using a D-optimal experimental design. Fresh and frozen-then-thawed samples were modelled, separately and in combination, by a classification (partial least squares discriminant analysis) and class-modelling (soft independent modelling of class analogy) approach. With the former, 100% correct classification accuracies were obtained separately for fresh and frozen-then-thawed material. Separate class-models for fresh and frozen-then-thawed samples exhibited high sensitivities (0.94 to 1.0) but lower specificities (0.33 – 0.80 for fresh samples and 0.41 – 0.87 for frozen-then-thawed samples). When fresh and frozen-then-thawed samples were modelled together, sensitivity remained 1.0 but specificity ranged from 0.29 to 0.91. Results indicate a role for this technique in monitoring beefburger compliance to label.
    • Detection of offal adulteration in beefburgers using near infrared reflectance spectroscopy and multivariate modelling

      Zhao, Ming; O'Donnell, Colm P.; Downey, Gerard; Food Safety Authority of Ireland; Teagasc Walsh Fellowship Programme (IM Publications, 2013)
      The main aim of this study was to develop a rapid and reliable tool using near infrared (NIR) reflectance spectroscopy to confirm beefburger authenticity in the context of offal (kidney, liver, heart and lung) adulteration. An experimental design was used to develop beefburger formulations to simultaneously maximise the variable space describing offal-adulterated samples and minimise the number of experiments required. Authentic (n = 36) and adulterated (n = 46) beefburger samples were produced using these formulations. Classification models (partial least squares discriminant analysis, PLS1-DA) and class-modelling tools (soft independent modelling of class analogy, SIMCA) were developed using raw and pre-treated NIR reflectance spectra (850-1098 nm wavelength range) to detect authentic and adulterated beefburgers in (1) fresh, (2) frozen-then-thawed and (3) fresh or frozen-then-thawed states. In the case of authentic samples, the best PLS1-DA models achieved 100% correct classification for fresh, frozen-then-thawed and fresh or frozen-then-thawed samples. SIMCA models correctly identified all the fresh samples but not all the frozen-then-thawed and fresh or frozen-then-thawed samples. For the adulterated samples, PLS1-DA models correctly classified 95.5% of fresh, 91.3% of frozen-then-thawed and 88.9% of fresh or frozen-then-thawed beefburgers. SIMCA models exhibited specificity values of 1 for both fresh and frozen-then-thawed samples, 0.99 for fresh or frozen-then-thawed samples; sensitivity values of 1, 0.88 and 0.97 were obtained for fresh, frozen-then-thawed and fresh or frozen-then-thawed products respectively. Quantitative models (PLS1 regression) using both 850-1098 nm and 1100-2498 nm wavelength ranges were developed to quantify (1) offal adulteration and (2) added fat in adulterated beefburgers, both fresh and frozen-then-thawed. Models predicted added fat in fresh samples with acceptable accuracy (RMSECV = 2.0; RPD = 5.9); usefully-accurate predictions of added fat in frozen-then-thawed samples were not obtained nor was prediction of total offal possible in either sample form.
    • Dietary Compounds Influencing the Sensorial, Volatile and Phytochemical Properties of Bovine Milk

      Clarke, Holly J.; Griffin, Carol; Rai, Dilip K.; O’Callaghan, Tom F.; O’Sullivan, Maurice G.; Kerry, Joseph P.; Kilcawley, Kieran N.; Teagasc Walsh Fellowship Programme; 2016071 (MDPI AG, 2019-12-19)
      The main aim of this study was to evaluate the volatile profile, sensory perception, and phytochemical content of bovine milk produced from cows fed on three distinct feeding systems, namely grass (GRS), grass/clover (CLV), and total mixed ration (TMR). Previous studies have identified that feed type can influence the sensory perception of milk directly via the transfer of volatile aromatic compounds, or indirectly by the transfer of non-volatile substrates that act as precursors for volatile compounds. In the present study, significant differences were observed in the phytochemical profile of the different feed and milk samples. The isoflavone formonoetin was significantly higher in CLV feed samples, but higher in raw GRS milk, while other smaller isoflavones, such as daidzein, genistein, and apigenin were highly correlated to raw CLV milk. This suggests that changes in isoflavone content and concentration in milk relate to diet, but also to metabolism in the rumen. This study also found unique potential volatile biomarkers in milk (dimethyl sulfone) related to feeding systems, or significant differences in the concentration of others (toluene, p-cresol, ethyl and methyl esters) based on feeding systems. TMR milk scored significantly higher for hay-like flavor and white color, while GRS and CLV milk scored significantly higher for a creamy color. Milk samples were easily distinguishable by their volatile profile based on feeding system, storage time, and pasteurization.
    • The eating quality of beef from young dairy bulls derived from two breed types at three ages from two different production systems

      Nian, Yingqun; Kerry, Joseph P.; Prendiville, Robert; Allen, Paul; Teagasc Walsh Fellowship Programme (Teagasc (Agriculture and Food Development Authority), Ireland, 08/07/2017)
      Expansion of the Irish dairy herd has led to more dairy breed male calves being available for beef production. This study investigated the physico-chemical and sensory characteristics of beef from Holstein-Friesian (HF) and Jersey × HF (JEX) young bulls fed pasture grass only or pasture grass plus 2 kg concentrate during their first grazing season and slaughtered at 15, 19 or 22 mo of age. Longissimus thoracis (LT) muscles were collected from 67 carcasses. Postmortem pH, ultimate pH (pHu), meat colour, chemical composition, collagen content and solubility were evaluated. After ageing for 21 d, Warner-Bratzler shear force and cooking loss were determined, and assessments by a trained sensory panel were conducted. Meat from older animals was darker. The pHu, moisture and ash contents decreased, while residual roast beef flavour length increased with age. However, increasing age to slaughter did not negatively influence tenderness. JEX beef had lower cooking loss, was darker and redder, in addition to having higher sensory scores for initial tenderness and fattiness than HF beef. Warner-Bratzler variables were positively correlated with cooking loss and chewiness and were negatively correlated with intramuscular fat (IMF) content, soluble collagen and initial tenderness. In summary, most young dairy bull beef samples were acceptably tender after 21 d of ageing and half of them had acceptable IMF content. Slaughter age affected beef colour, pHu, chemical composition and flavour length. The eating quality of meat from the JEX breed type was considered to be superior to that of the HF breed type. Diet during the first season had no effect on meat quality traits.
    • Effect of finishing diet and duration on the sensory quality and volatile profile of lamb meat

      Gkarane, Vasiliki; Brunton, Nigel; Allen, Paul; Gravador, Rufielyn S.; Claffey, Noel A.; Diskin, Michael G.; Fahey, Alan G.; Farmer, Linda J.; Moloney, Aidan P; Alcalde, Maria J.; et al. (Elsevier, 2018-08-02)
      Animal production factors can affect the sensory quality of lamb meat. The study investigated the effect of diet composition and duration of consumption on the proximate analysis, volatile profile and sensory quality of lamb meat. Ninety-nine male Texel × Scottish Blackface lambs were raised at pasture for 10 months before being assigned in groups of 11 to one of the following treatments: 100% Silage (S) for 36 (S36), 54 (S54) or 72 (S72) days; 50% Silage - 50% Concentrate (SC) for 36 (SC36), 54 (SC54) or 72 (SC72) days; 100% Concentrate (C) for 36 (C36) or 54 (C54) or 72 (C72) days. A trained sensory panel found Intensity of Lamb Aroma, Dry Aftertaste and Astringent Aftertaste to be higher in meat from lambs on the concentrate diet. Discriminant analysis showed that the volatile profile enabled discrimination of lamb based on dietary treatment but the volatile differences were insufficient to impact highly on sensory quality. Muscle from animals in the S54 group had higher Manure/Faecal Aroma and Woolly Aroma than the SC54 and C54 groups, possibly related to higher levels of indole and skatole. Further research is required to establish if these small differences would influence consumer acceptability.
    • Effect of milk centrifugation and incorporation of high heat-treated centrifugate on the microbial composition and levels of volatile organic compounds of Maasdam cheese

      Lamichhane, Prabin; Pietrzyk, Anna; Feehily, Conor; Cotter, Paul D.; Mannion, David T.; Kilcawley, Kieran; Kelly, Alan L.; Sheehan, Diarmuid (JJ); Dairy Levy Trust; Teagasc Walsh Fellowship Programme; et al. (Elsevier, 2018-03-15)
      Centrifugation is a common milk pretreatment method for removal of Clostridium spores which, on germination, can produce high levels of butyric acid and gas, resulting in rancid, gassy cheese. The aim of this study was to determine the effect of centrifugation of milk, as well as incorporation of high heat-treated centrifugate into cheese milk, on the microbial and volatile profile of Maasdam cheese. To facilitate this, 16S rRNA amplicon sequencing in combination with a selective media-based approach were used to study the microbial composition of cheese during maturation, and volatile organic compounds within the cheese matrix were analyzed by HPLC and solid-phase microextraction coupled with gas chromatography–mass spectrometry. Both culture-based and molecular approaches revealed major differences in microbial populations within the cheese matrix before and after warm room ripening. During warm room ripening, an increase in counts of propionic acid bacteria (by ∼101.5 cfu) and nonstarter lactic acid bacteria (by ∼108 cfu) and a decrease in the counts of Lactobacillus helveticus (by ∼102.5 cfu) were observed. Lactococcus species dominated the curd population throughout ripening, followed by Lactobacillus, Propionibacterium, and Leuconostoc, and the relative abundance of these accounted for more than 99% of the total genera, as revealed by high-throughput sequencing. Among subdominant microflora, the overall relative abundance of Clostridium sensu stricto was lower in cheeses made from centrifuged milk than control cheeses, which coincided with lower levels of butyric acid. Centrifugation as well as incorporation of high heat-treated centrifugate into cheese milk seemed to have little effect on the volatile profile of Maasdam cheese, except for butyric acid levels. Overall, this study suggests that centrifugation of milk before cheesemaking is a suitable method for controlling undesirable butyric acid fermentation without significantly altering the levels of other volatile organic compounds of Maasdam cheese.
    • Effect of pulse flours on the physiochemical characteristics and sensory acceptance of baked crackers

      Millar, Kim A.; Barry-Ryan, Catherine; Burke, Roisin; Hussey, Karen; McCarthy, Sinead N.; Gallagher, Eimear; Teagasc Walsh Fellowship Programme (Wiley, 29/03/2017)
      Pulse flours offer nutritional alternatives to wheat flour in the production of baked snacks due to their high protein and fibre levels and low glycaemic index. In this study, broad-bean (Vicia faba), yellow-pea and green-pea (Pisum sativum) flours were each blended with wheat flour at 40% in the formulation of chemically leavened crackers. The effects of flour type and baking time on the physiochemical properties, sensory acceptability, nutritional composition and antioxidant activity of the crackers were observed in comparison with 100% wheat crackers. Broad-bean crackers had the highest protein content and antioxidant activity (13 g per 100 g DM and 38.8 mgAAE per 100 g DM, respectively). Yellow-pea crackers had the highest fibre content (12 g per 100 g DM). Physical dimensions and colour attributes were significantly affected by pulse-flour substitution. Yellow-pea and broad-bean crackers were significantly preferred by consumers compared to the control, demonstrating the potential application of these flours to improve the eating quality and nutritional profile of crackers.
    • The effect of temperature during retail display on the colour stability of CO pretreated vacuum packaged beef steaks

      Van Rooyen, Lauren Anne; Allen, Paul; Gallagher, Eimear; O'Connor, David I.; Teagasc Walsh Fellowship Programme; Department of Agriculture, Food and the Marine; 11/F/060 (Elsevier, 2018-05-24)
      The effect of CO pretreatments applied to beef striploin steaks (Longissimus thoracis et lumborum, LTL) prior to vacuum packaging and display temperature on colour stability, shelf life and tenderness was determined. Steaks were exposed to 5% CO, 60% CO2 and 35% N2 for 3 (CO3), 5 (CO5) or 7 (CO7) h, followed by 28 days display at 2 °C (good industry practice) or 6 °C (mild abuse). CO5 was the optimum exposure time as it induced the desirable colour while not retaining the bright colour, irrespective of display temperature. K/S ratios confirmed that CO pretreatment did not mask spoilage and could be more sensitive than colour parameters at monitoring discoloration as colour was not retained. Exposure to CO did not have any negative effect on meat quality attributes, while mild temperature abuse (6 °C) increased purge loss and decreased pH.
    • Genome Sequence of Staphylococcus saprophyticus DPC5671, a Strain Isolated from Cheddar Cheese

      Bertuzzi, Andrea; Guinane, Caitriona M.; Crispie, Fiona; Kilcawley, Kieran; McSweeney, Paul L. H.; Rea, Mary; Teagasc Walsh Fellowship Programme (American Society for Microbiology, 20/04/2017)
      The draft genome sequence of Staphylococcus saprophyticus DPC5671, isolated from cheddar cheese, was determined. S. saprophyticus is a common Gram-positive bacterium detected on the surface of smear-ripened cheese and other fermented foods.
    • In vitro digestion of protein-enriched restructured beef steaks with pea protein isolate, rice protein and lentil flour following sous vide processing

      Baugreet, Sephora; Gomez, Carolina; Auty, Mark; Kerry, Joseph P.; Hamill, Ruth; Brodkorb, Andre; Teagasc Walsh Fellowship Programme; Department of Agriculture, Food and the Marine; 11/F/045 (Elsevier, 2019-04-12)
      The effect of plant protein inclusion in cooked meat upon in vitro gastro-intestinal (GI) digestion was investigated. Pea protein isolate, rice protein and lentil flour were used to increase the protein content in a meat model system restructured using two transglutaminase enzymes [Activa®EB (TG) and Transgluseen™-M (TS)]. Restructured beef steaks were subjected to simulated GI digestion using the static INFOGEST method. Samples taken at different digestion times were analysed using SDS-PAGE, size exclusion-HPLC, free amino acid analysis and microscopy. SDS-PAGE analysis revealed significant protein hydrolysis during GI digestion. Most soluble peptides had a molecular weight smaller than 500 Da, corresponding to peptides of <5 amino acids, regardless of food treatment. The amounts of released, free amino acids isoleucine, lysine, phenylalanine and valine were higher (P < 0.05) in lentil-enriched restructured beef steaks following GI digestion. Confocal laser scanning microscopy (CSLM) revealed pronounced aggregation in digested samples. In vitro digestates of protein-enriched restructured beef steaks showed lower production of small molecular weight peptides. This study demonstrated how the bioaccessibility of protein-enriched restructured beef steaks are influenced by formulation and processing.
    • Influence of chaperone-like activity of caseinomacropeptide on the gelation behaviour of whey proteins at pH 6.4 and 7.2.

      Gaspard, Sophie J.; Sharma, Prateek; Fitzgerald, Ciarán; Tobin, John T.; O’Mahony, James A.; Kelly, Alan L.; Brodkorb, Andre; Dairy Research Ireland; Teagasc Walsh Fellowship Programme; European Union; et al. (Elsevier, 2020-08-15)
      The effect of caseinomacropeptide (CMP) on the heat-induced denaturation and gelation of whey proteins (2.5–10%, w/v) at pH 6.4 and 7.2, at a whey protein:CMP ratio of 1:0.9 (w/w), was investigated using differential scanning calorimetry (DSC), oscillatory rheology (90 °C for 20 min) and confocal microscopy. Greater frequency-dependence in the presence of CMP suggested that the repulsive interactions between CMP and the whey proteins affected the network generated by the non-heated whey protein samples. At pH 6.4 or 7.2, CMP increased the temperature of denaturation of β-lactoglobulin by up to 3 °C and increased the gelation temperature by up to 7 °C. The inclusion of CMP strongly affected the structure of the heat-induced whey protein gels, resulting in a finer stranded structure at pH 6.4 and 7.2. The presence of CMP combined with a lower heating rate (2 °C/min) prevented the formation of a solid gel of whey proteins after heating for 20 min at 90 °C and at pH 7.2. These results show the potential of CMP for control of whey protein denaturation and gelation.
    • Optimisation of plant protein and transglutaminase content in novel beef restructured steaks for older adults by central composite design

      Baugreet, Sephora; Kerry, Joseph P.; Brodkorb, Andre; Gomez, Carolina; Auty, Mark; Allen, Paul; Hamill, Ruth; Department of Agriculture, Food and the Marine, Ireland; Teagasc Walsh Fellowship Programme; 11/F/045 (Elsevier, 2018-03-29)
      With the goal of optimising a protein-enriched restructured beef steak targeted at the nutritional and chemosensory requirements of older adults, technological performance of thirty formulations, containing plant-based ingredients, pea protein isolate (PPI), rice protein (RP) and lentil flour (LF) with transglutaminase (TG) to enhance binding of meat pieces, were analysed. Maximal protein content of 28% in cooked product was achieved with PPI, RP and LF. Binding strength was primarily affected by TG, while textural parameters were improved with LF inclusion. Optimal formulation (F) to obtain a protein-enriched steak with lowest hardness values was achieved with TG (2%), PPI (8%), RP (9.35%) and LF (4%). F, F1S (optimal formulation 1 with added seasoning) and control restructured products (not containing plant proteins or seasonings) were scored by 120 consumers' aged over-65 years. Controls were most preferred (P < .05), while F1S were least liked by the older consumers. Consumer testing suggests further refinement and optimisation of restructured products with plant proteins should be undertaken.
    • Optimisation of plant protein and transglutaminase content in novel beef restructured steaks for older adults by central composite design

      Baugreet, Sephora; Kerry, Joesph; Brodkorb, Andre; Gomez, Carolina; Auty, Mark; Allen, Paul; Hamill, Ruth; Teagasc Walsh Fellowship Programme; Department of Agriculture, Food and the Marine; 11/F/045 (Elsevier, 2018-03-29)
      With the goal of optimising a protein-enriched restructured beef steak targeted at the nutritional and chemosensory requirements of older adults, technological performance of thirty formulations, containing plant-based ingredients, pea protein isolate (PPI), rice protein (RP) and lentil flour (LF) with transglutaminase (TG) to enhance binding of meat pieces, were analysed. Maximal protein content of 28% in cooked product was achieved with PPI, RP and LF. Binding strength was primarily affected by TG, while textural parameters were improved with LF inclusion. Optimal formulation (F) to obtain a protein-enriched steak with lowest hardness values was achieved with TG (2%), PPI (8%), RP (9.35%) and LF (4%). F, F1S (optimal formulation 1 with added seasoning) and control restructured products (not containing plant proteins or seasonings) were scored by 120 consumers' aged over-65 years. Controls were most preferred (P < .05), while F1S were least liked by the older consumers. Consumer testing suggests further refinement and optimisation of restructured products with plant proteins should be undertaken.
    • Optimization of protein recovery from bovine lung by pH shift process using response surface methodology

      Lynch, Sarah A.; Álvarez García, Carlos; O'Neill, Eileen; Keenan, Derek F.; Mullen, Anne Maria; Department of Agriculture, Food and the Marine, Ireland; Teagasc Walsh Fellowship Programme; 11/F/043 (Wiley, 2017-09)
      BACKGROUND Response surface methodology (RSM) was used in a sequential manner to optimize solubilization and precipitation conditions in the recovery of protein from bovine lung using pH shift. RESULTS Separate D‐optimal designs were employed for protein solubilization and precipitation. Independent variables investigated for protein solubilization were time (10–120 min), temperature (4–20 °C), pH (8.0–11.0) and solvent/sample ratio (2.5–10). Variables for protein precipitation were time (0–60 min) and pH (4.25–6.00). Soluble protein yields ranged from 323 to 649 g kg−1 and the quadratic model for protein solubilization revealed a coefficient of determination R2 of 0.9958. Optimal conditions for maximum protein solubility were extraction time 140 min, temperature 19 °C, pH 10.8 and solvent/sample ratio 13.02. Protein precipitation yields varied from 407 to 667 g kg−1, giving a coefficient of determination R2 of 0.9335. Optimal conditions for maximum protein precipitation were pH 5.03 and 60 min. Based on the RSM model, solubilization conditions were manipulated to maximize protein solubilization under reduced water and alkaline usage. These conditions were also validated. CONCLUSION Models for solubilization and precipitation using bovine and porcine lung were validated; predicted and actual yields were in good agreement, showing cross‐species applicability of the results. © 2017 Society of Chemical Industry
    • Performances of full cross-validation partial least squares regression models developed using Raman spectral data for the prediction of bull beef sensory attributes

      Zhao, Ming; Nian, Yingqun; Allen, Paul; Downey, Gerard; Kerry, Joseph P.; O’Donnell, Colm P.; Teagasc Walsh Fellowship Programme (Elsevier BV, 2018-04-23)
      The data presented in this article are related to the research article entitled “Application of Raman spectroscopy and chemometric techniques to assess sensory characteristics of young dairy bull beef” [1]. Partial least squares regression (PLSR) models were developed on Raman spectral data pre-treated using Savitzky Golay (S.G.) derivation (with 2nd or 5th order polynomial baseline correction) and results of sensory analysis on bull beef samples (n = 72). Models developed using selected Raman shift ranges (i.e. 250–3380 cm−1, 900–1800 cm−1 and 1300–2800 cm−1) were explored. The best model performance for each sensory attributes prediction was obtained using models developed on Raman spectral data of 1300–2800 cm−1.
    • Physicochemical Characteristics of Protein-Enriched Restructured Beef Steaks with Phosphates, Transglutaminase, and Elasticised Package Forming

      Baugreet, Sephora; Kerry, Joseph P.; Allen, Paul; Gallagher, Eimear; Hamill, Ruth; Irish Department of Agriculture, Food and the Marine; Teagasc Walsh Fellowship Programme; 11/F/045 (Hindawi Limited, 2018)
      Restructured beef steaks were formulated by adding protein-rich ingredients (pea protein isolate (PPI), rice protein (RP), and lentil flour (LF) (at 4 and 8%)), phosphate (0.2%), and two binding agents: 1% (TG) and 0.15% (TS). The effects of their addition on the physicochemical properties of the beef steaks were investigated. Protein content of the RP8TG sample was significantly higher than that of the control in both the raw and cooked state. Raw LF4TS exhibited greater () a values than the control; however, after the cooking process, L, a, and b values were similar for all treatments. Textural assessment showed that elevating protein level increased () hardness, chewiness, cohesiveness, and gumminess in cooked restructured steaks. LF addition reduced all textural values assessed, indicating a strong plant protein effect on texture modification. The commercial binder produced a better bind in combination with protein ingredients. This facilitated the production of uniformed restructured beef steaks from low-value beef muscles with acceptable quality parameters using a novel process technology.