The aim of the Food Chemistry & Technology Department is to help food processors maintain competitive advantage and secure premium markets. Our Dairy research focuses on cheese, infant formula and dairy based ingredients; Meat research, focusing on quality, whole chain management and recovering value from meat processing streams; Cereal research focusing on product quality and innovation in the bakery industry

Recent Submissions

  • Thermal gelation and hardening of whey protein beads for subsequent dehydration and encapsulation using vitrifying sugars

    Hansen, Mackenzie M.; Maidannyk, Valentyn; Roos, Yrjö H.; Lauritzson Foundation; University College Cork (Elsevier BV, 2020-08)
    Solid beads were developed using whey protein isolate (WPI) and sugars for controlled hardening and vitrification of wall materials. A concentrated mixture of WPI and sucrose in water, intended for use as gelling and glass-forming ingredients, respectively, was used to form liquid feeds with varying pH, viscosities, surface tensions, solids contents and compositions. Using a peristaltic pump, feeds flowed continuously through silicon tubing and formed droplets. Rapid solidification occurred when droplets were submerged in heated, stirred oil; beads were harvested for vacuum oven drying. Dispersions were characterized by viscosity and flow testing. Dried beads were characterized for porosity, hardness, diameters, and water activity, and microstructures were analyzed with microscopy. Drop-forming dispersions comprised of 40% WPI with 10% sucrose by mass possessed structure forming and shape retention qualities. Feed composition influenced characteristics of the final product more strongly than processing conditions including heating times and temperatures.
  • Fabrication of Ligusticum chuanxiong polylactic acid microspheres: A promising way to enhance the hepatoprotective effect on bioactive ingredients

    Ge, Huifang; Lin, Peixuan; Luo, Taiduan; Yan, Zhiming; Xiao, Jianbo; Miao, Song; Chen, Jichen; National Natural Science Foundation of China; Natural Science Foundation of Fujian Province; No. 31201350; et al. (Elsevier BV, 2020-07)
    Ligusticum chuanxiong extract-polylactic acid sustained-release microspheres (LCE-PLA) are fabricated in this study for enhancing both duration and hepatoprotective efficacy of the main bioactive ingredients. LCE-PLA in vitro release, cytotoxicity and in vivo hepatoprotective effect were discussed to evaluate its efficiency and functionality. Results demonstrated that the optimal drug-loading rate and encapsulation efficiency of tetramethylpyrazine (TMP, the main active ingredient) were 8.19%, 83.72%, respectively. The LCE-PLA in vitro release of TMP showed prolong 5-fold and in vitro cytotoxicity declined 25.00% compared with naked LCE. After 6 weeks of in vivo intervention in high fat diet mice, both liver aspartate aminotransferase and alanine aminotransferase levels were higher in LCE-PLA group than LCE group. The above results indicated that TMP had a higher bioavailability of hepatoprotection when encapsulation of LCE-PLA was applied. The current study has provided a promising novel way to enhance the efficacy of short half-life ingredients.
  • Influence of sodium hexametaphosphate addition on the functional properties of milk protein concentrate solutions containing transglutaminase cross-linked proteins

    Power, Orla M.; Fenelon, Mark; O'Mahony, James A.; McCarthy, Noel; Teagasc Wash Fellowship Programme (Elsevier BV, 2020-05)
    The functional properties of milk protein concentrate (MPC) powders are often hindered by their poor solubility. Calcium chelating salts have been shown to improve powder solubility, but generally their action contributes to higher viscosity due to disintegration of casein micelles and higher levels of serum-phase calcium. To help mitigate increases in viscosity associated with calcium chelation, transglutaminase (TGase), an enzyme that covalently crosslinks protein, was employed in an effort to stabilise the casein micelle structure. Sodium hexametaphosphate (SHMP) was added to control (C-MPC) and TGase crosslinked MPC (TG-MPC) dispersions at concentrations of 5, 12.5 and 25 mm prior to analysis. TG-MPC dispersions had lower viscosity than C-MPC dispersions across all SHMP concentrations studied. Crosslinking limited micelle dissociation on SHMP addition and led to greater retention of the white colour of the protein dispersions, while the turbidity of C-MPC dispersions decreased with increasing SHMP addition.
  • Review of near-infrared spectroscopy as a process analytical technology for real-time product monitoring in dairy processing

    Pu, Yuan-Yuan; O'Donnell, Colm; Tobin, John T.; O'Shea, Norah; Dairy Processing Technology Centre; Enterprise Ireland; TC/2014/0016 (Elsevier BV, 2020-04)
    Real-time process/product monitoring can be achieved using suitable process analytical technologies (PAT) to improve process efficiencies and product quality. In the dairy industry, near infrared (NIR) spectroscopy has been utilised as a laboratory analytical method (off-line) for compositional analysis of dairy products since the 1970s. Recent advances in NIR technology and instrumentation have widened its applications from a bench-top analytical instrument to a promising PAT tool for on-line and in-line implementation. This review focuses on the use of NIR technology for real-time monitoring of dairy products, by briefly outlining the measurement principle, NIR instrument configurations, in-line sampling methods, calibration models development, some practical considerations for process installation, and current state of the art in on-line and in-line NIR applications (2012 to date) for continuous process monitoring in the production of dairy products. The challenges and additional resources required to improve production efficiencies using NIR spectroscopy are also discussed.
  • Fabrication and characterization of highly re-dispersible dry emulsions

    Lu, Wei; Maidannyk, Valentyn; Kelly, Alan L.; Miao, Song; Shanghai Pujiang Program; Shanghai Jiao Tong University; 19PJ1406500; 19X100040028 (Elsevier BV, 2020-05)
    Highly re-dispersible dry emulsions were obtained through drying konjac glucomannan (KGM) or monoglyceride (MG) structured O/W emulsions. Emulsion powders showed different morphologies, particle size and surface microstructures, depending on the drying method (spray/freeze-drying), and the emulsion compositions. The introduction of a low level of KGM (0.15 wt%) and MG (1 wt%) significantly reduced the level of maltodextrin as wall material. All powdered emulsions showed rapid re-hydration in water. Compared with original emulsions before drying, re-constituted emulsions from spray-dried powders showed slightly increased mean droplet size while that from freeze-dried ones showed slightly decreased mean droplet size. KGM significantly decreased the initial viscosity (p < 0.05) but increased the creaming stability (p < 0.05) of re-constituted emulsions. Measurement of β-carotene content in re-constituted oil droplets fractions indicated that emulsion powders have good re-dispersibility in water (>93% in average). The findings in this study make it possible to obtain emulsion powders and their reconstitutions with desired properties by structuring the original emulsions before drying, and confirmed the possibility of KGM and MG in producing low-cost emulsion powders and the potential of these dry emulsions as novel solid delivery carriers for lipophilic components.
  • Dynamic in situ imaging of semi-hard cheese microstructure under large-strain tensile deformation: Understanding structure-fracture relationships

    Lamichhane, Prabin; Auty, Mark A.E.; Kelly, Alan L.; Sheehan, Diarmuid (JJ); Dairy Research Ireland; Ornua; Teagasc Walsh Fellowship Programme; RMIS 6259 (Elsevier BV, 2020-04)
    Changes in the microstructure of semi-hard cheeses were observed in situ under tensile deformation by placing a microtensile stage directly under a confocal scanning laser microscope, and recording force/displacement data simultaneously. On tensile deformation, detachment of fat globules and their subsequent release from the cheese matrix were observed, suggesting that they are weakly bonded to or entrapped within the cheese matrix. Moreover, an inherent micro-defect was observed at a curd granule junction within the cheese matrix, which fractured along the curd granule junction under tensile deformation, suggesting that such micro-defects could be a key to the formation of undesirable slits or cracks. Furthermore, the fracture behaviour of semi-hard cheese varied with ripening temperature, coagulant type, and inhibition of residual chymosin activity. Overall, this study demonstrated the potential of dynamic in situ imaging of cheese microstructure for developing a greater understanding of the breakdown behaviour of cheese matrices.
  • Microfiltration of raw milk for production of high-purity milk fat globule membrane material

    Hansen, Steffen F.; Hogan, Sean; Tobin, John; Rasmussen, Jan T.; Larsen, Lotte B.; Wiking, Lars; Arla Foods for Health Centre; Arla Food Ingredients; Innovation Fund Denmark; 5158-00014B (Elsevier BV, 2020-07)
    Commercial ingredients containing milk fat globule membrane (MFGM) material are currently isolated from heavily processed dairy streams. The aim of this study was to achieve a more gentle isolation of MFGM material by means of ceramic dia-microfiltration of raw whole milk to separate fat globules from casein micelles and whey proteins prior to MFGM extraction. A pilot-scale experiment with 1.4 μm pore size (membrane surface area 1.05 m2) resulted in an optimal outcome of low permeation of fat (2.5% permeation) and high permeation of proteins (97% permeation). This yielded an MFGM isolate with 7% w/w polar lipids and 30% w/w proteins, where contamination of non-MFGM proteins was only 25% of total protein content. Furthermore, mild pasteurization (72 °C, 15 s) introduced either before or after microfiltration had no impact on filtration efficiency or MFGM yield and composition. The work describes an industrially relevant production method for a less-processed MFGM material of high purity with potential for further separation and valorisation of protein-rich permeate streams.
  • Urease and Nitrification Inhibitors—As Mitigation Tools for Greenhouse Gas Emissions in Sustainable Dairy Systems: A Review

    Byrne, Maria P.; Tobin, John T.; Forrestal, Patrick J.; Danaher, Martin; Nkwonta, Chikere; Richards, Karl; Cummins, Enda; Hogan, Sean A.; O'Callaghan, Tom; Department of Agriculture Food and the Marine; et al. (MDPI AG, 2020-07-27)
    Currently, nitrogen fertilizers are utilized to meet 48% of the total global food demand. The demand for nitrogen fertilizers is expected to grow as global populations continue to rise. The use of nitrogen fertilizers is associated with many negative environmental impacts and is a key source of greenhouse and harmful gas emissions. In recent years, urease and nitrification inhibitors have emerged as mitigation tools that are presently utilized in agriculture to prevent nitrogen losses and reduce greenhouse and harmful gas emissions that are associated with the use of nitrogen-based fertilizers. Both classes of inhibitor work by different mechanisms and have different physiochemical properties. Consequently, each class must be evaluated on its own merits. Although there are many benefits associated with the use of these inhibitors, little is known about their potential to enter the food chain, an event that may pose challenges to food safety. This phenomenon was highlighted when the nitrification inhibitor dicyandiamide was found as a residual contaminant in milk products in 2013. This comprehensive review aims to discuss the uses of inhibitor technologies in agriculture and their possible impacts on dairy product safety and quality, highlighting areas of concern with regards to the introduction of these inhibitor technologies into the dairy supply chain. Furthermore, this review discusses the benefits and challenges of inhibitor usage with a focus on EU regulations, as well as associated health concerns, chemical behavior, and analytical detection methods for these compounds within milk and environmental matrices.
  • Assessing the Carbon Emission Driven by the Consumption of Carbohydrate-Rich Foods: The Case of China

    Yang, Xiaoke; Zhang, Zhihang; Chen, Huangyixin; Zhao, Rongrong; Xu, Zhongyue; Xie, Anguo; Chen, Qiuhua; Fujian Provincial Social Science Research Base for Ecological Civilization; Guangdong Planning Projects of Philosophy and Social Science; Natural Science Foundation of Guangdong Province; et al. (MDPI AG, 2019-03-28)
    Background: Carbohydrate-rich (CR) foods are essential parts of the Chinese diet. However, CR foods are often given less attention than animal-based foods. The objectives of this study were to analyze the carbon emissions caused by CR foods and to generate sustainable diets with low climate impact and adequate nutrients. Methods: Twelve common CR food consumption records from 4857 individuals were analyzed using K-means clustering algorithms. Furthermore, linear programming was used to generate optimized diets. Results: Total carbon emissions by CR foods was 683.38g CO2eq per day per capita, accounting for an annual total of 341.9Mt CO2eq. All individuals were ultimately divided into eight clusters, and none of the popular clusters were low carbon or nutrient sufficient. Optimized diets could reduce about 40% of carbon emissions compared to the average current diet. However, significant structural differences exist between the current diet and optimized diets. Conclusions: To reduce carbon emissions from the food chain, CR foods should be a research focus. Current Chinese diets need a big change to achieve positive environmental and health goals. The reduction of rice and wheat-based foods and an increase of bean foods were the focus of structural dietary change in CR food consumption.
  • The Use of High Performance Liquid Chromatography for the Characterization of the Unfolding and Aggregation of Dairy Proteins

    Gaspard, Sophie; Brodkorb, Andre; Dairy Levy Research Trust; Food Institutional Research Measure; Enterprise Ireland; Teagasc Walsh Fellowship Programme; MDDT6261; 08RDTMFRC650; CC20080001; 2012211 (Springer New York, 2019-07-25)
    High-performance liquid chromatography (HPLC) is routinely used to identify and characterize proteins. HPLC can help to understand protein aggregation processes in dairy products, which are induced by common industrial processing steps such as heat treatment. In this chapter, three complementary chromatographic methods are described, which are based on the principles of size exclusion and reversed-phase chromatography. These methods are used to determine the degree of denaturation and aggregation of proteins, and estimate the molecular weight of these aggregates.
  • Influence of high-pressure processing on quality attributes of haddock and mackerel minces during frozen storage, and fishcakes prepared thereof

    Cropotova, Janna; Mozuraityte, Revilija; Standal, Inger Beate; Ojha, Shikha; Rustad, Turid; Tiwari, Brijesh K; JPI; RCN 259582/E50 (Elsevier BV, 2020-01)
  • Investigation of Raman Spectroscopy (with Fiber Optic Probe) and Chemometric Data Analysis for the Determination of Mineral Content in Aqueous Infant Formula

    Zhao, Ming; Shaikh, Saif; Kang, Renxi; Markiewicz-Keszycka, Maria (MDPI AG, 2020-07-22)
    This study investigated the use of Raman spectroscopy (RS) and chemometrics for the determination of eight mineral elements (i.e., Ca, Mg, K, Na, Cu, Mn, Fe, and Zn) in aqueous infant formula (INF). The samples were prepared using infant formula powder reconstituted to concentrations of 3%–13% w/w (powder: water) (n = 83). Raman spectral data acquisition was carried out using a non-contact fiber optic probe on the surface of aqueous samples in 50–3398 cm−1. ICP-AES was used as a reference method for the determination of the mineral contents in aqueous INF samples. Results showed that the best performing partial least squares regression (PLSR) models developed for the prediction of minerals using all samples for calibration achieved R2CV values of 0.51–0.95 with RMSECVs of 0.13–2.96 ppm. The PLSR models developed and validated using separate calibration (n = 42) and validation (n = 41) samples achieved R2CVs of 0.93, 0.94, 0.91, 0.90, 0.97, and 0.94, R2Ps of 0.75, 0.77, 0.31, 0.60, 0.84, and 0.80 with RMSEPs of 3.17, 0.29, 3.45, 1.51, 0.30, and 0.25 ppm for the prediction of Ca, Mg, K, Na, Fe, and Zn respectively. This study demonstrated that RS equipped with a non-contact fiber optic probe and combined with chemometrics has the potential for timely quantification of the mineral content of aqueous INF during manufacturing.
  • WO 2018/114971 A1 A method for producing beads

    Brodkorb, Andre; Haque, Kamrul; Teagasc Agriculture and Food Development Authority (2020-10-19)
    The current invention relates to a method for producing beads. In particular, the current invention relates to a method for producing microbeads. The invention also relates to a microbead preparation produced by the method of the invention.
  • Using a reaction‐diffusion model to estimate day respiration and reassimilation of (photo)respiredCO2in leaves

    Berghuijs, Herman N. C.; Yin, Xinyou; Ho, Q. Tri; Retta, Moges A.; Nicolaï, Bart M.; Struik, Paul C.; the BioSolar Cells programme; Research Council of the KU Leuven; project C16/ 16/002 (Wiley, 2019-05-11)
    Methods using gas exchange measurements to estimate respiration in the light (day respiration Rd) make implicit assumptions about reassimilation of (photo)respired CO2; however, this reassimilation depends on the positions of mitochondria. We used a reaction-diffusion model without making these assumptions to analyse datasets on gas exchange, chlorophyll fluorescence and anatomy for tomato leaves. We investigated how Rd values obtained by the Kok and the Yin methods are affected by these assumptions and how those by the Laisk method are affected by the positions of mitochondria. The Kok method always underestimated Rd. Estimates of Rd by the Yin method and by the reaction-diffusion model agreed only for nonphotorespiratory conditions. Both the Yin and Kok methods ignore reassimilation of (photo)respired CO2, and thus underestimated Rd for photorespiratory conditions, but this was less so in the Yin than in the Kok method. Estimates by the Laisk method were affected by assumed positions of mitochondria. It did not work if mitochondria were in the cytosol between the plasmamembrane and the chloroplast envelope. However, mitochondria were found to be most likely between the tonoplast and chloroplasts. Our reaction-diffusion model effectively estimates Rd, enlightens the dependence of Rd estimates on reassimilation and clarifies (dis)advantages of existing methods.
  • Use of Lactic Acid Bacteria to Reduce Methane Production in Ruminants, a Critical Review

    Doyle, Natasha; Mbandlwa, Philiswa; Kelly, William J.; Attwood, Graeme; Li, Yang; Ross, R. Paul; STANTON, CATHERINE; Leahy, Sinead; European Union; Teagasc Walsh Fellowship Programme; et al. (Frontiers Media SA, 2019-10-01)
    Enteric fermentation in ruminants is the single largest anthropogenic source of agricultural methane and has a significant role in global warming. Consequently, innovative solutions to reduce methane emissions from livestock farming are required to ensure future sustainable food production. One possible approach is the use of lactic acid bacteria (LAB), Gram positive bacteria that produce lactic acid as a major end product of carbohydrate fermentation. LAB are natural inhabitants of the intestinal tract of mammals and are among the most important groups of microorganisms used in food fermentations. LAB can be readily isolated from ruminant animals and are currently used on-farm as direct-fed microbials (DFMs) and as silage inoculants. While it has been proposed that LAB can be used to reduce methane production in ruminant livestock, so far research has been limited, and convincing animal data to support the concept are lacking. This review has critically evaluated the current literature and provided a comprehensive analysis and summary of the potential use and mechanisms of LAB as a methane mitigation strategy. It is clear that although there are some promising results, more research is needed to identify whether the use of LAB can be an effective methane mitigation option for ruminant livestock.
  • Fortified Blended Food Base: Effect of Co-Fermentation Time on Composition, Phytic Acid Content and Reconstitution Properties

    Shevade, Ashwini; O’Callaghan, Yvonne; O’Brien, Nora; O’Connor, Tom; Guinee, Timothy; Department of Agriculture, Food and the Marine; 14/F/805 (MDPI AG, 2019-09-03)
    Dehydrated blends of dairy-cereal combine the functional and nutritional properties of two major food groups. Fortified blended food base (FBFB) was prepared by blending fermented milk with parboiled wheat, co-fermenting the blend at 35 ◦C, shelf-drying and milling. Increasing co-fermentation time from 0 to 72 h resulted in powder with lower lactose, phytic acid and pH, and higher contents of lactic acid and galactose. Simultaneously, the pasting viscosity of the reconstituted base (16.7%, w/w, total solids) and its yield stress (σ0), consistency index (K) and viscosity on shearing decreased significantly. The changes in some characteristics (pH, phytic acid, η120) were essentially complete after 24 h co-fermentation while others (lactose, galactose and lactic acid, pasting viscosities, flowability) proceeded more gradually over 72 h. The reduction in phytic acid varied from 40 to 58% depending on the pH of the fermented milk prior to blending with the parboiled cereal. The reduction in phytic acid content of milk (fermented milk)-cereal blends with co-fermentation time is nutritionally desirable as it is conducive to an enhanced bioavailability of elements, such as Ca, Mg, Fe and Zn in milk-cereal blends, and is especially important where such blends serve as a base for fortified-blended foods supplied to food-insecure regions
  • Online Prediction of Physico-Chemical Quality Attributes of Beef Using Visible—Near-Infrared Spectroscopy and Chemometrics

    Sahar, Amna; Allen, Paul; Sweeney, Torres; Cafferky, Jamie; Downey, Gerard; Cromie, Andrew; Hamill, Ruth; Department of Food, Agriculture and the Marine; 11/SF/311 (MDPI AG, 2019-10-23)
    The potential of visible–near-infrared (Vis–NIR) spectroscopy to predict physico-chemical quality traits in 368 samples of bovine musculus longissimus thoracis et lumborum (LTL) was evaluated. A fibre-optic probe was applied on the exposed surface of the bovine carcass for the collection of spectra, including the neck and rump (1 h and 2 h post-mortem and after quartering, i.e., 24 h and 25 h post-mortem) and the boned-out LTL muscle (48 h and 49 h post-mortem). In parallel, reference analysis for physico-chemical parameters of beef quality including ultimate pH, colour (L, a*, b*), cook loss and drip loss was conducted using standard laboratory methods. Partial least-squares (PLS) regression models were used to correlate the spectral information with reference quality parameters of beef muscle. Different mathematical pre-treatments and their combinations were applied to improve the model accuracy, which was evaluated on the basis of the coefficient of determination of calibration (R2C) and cross-validation (R2CV) and root-mean-square error of calibration (RMSEC) and cross-validation (RMSECV). Reliable cross-validation models were achieved for ultimate pH (R2CV: 0.91 (quartering, 24 h) and R2CV: 0.96 (LTL muscle, 48 h)) and drip loss (R2CV: 0.82 (quartering, 24 h) and R2CV: 0.99 (LTL muscle, 48 h)) with lower RMSECV values. The results show the potential of Vis–NIR spectroscopy for online prediction of certain quality parameters of beef over different time periods.
  • Effect of Diet on the Vitamin B Profile of Bovine Milk-Based Protein Ingredients

    Magan, Jonathan B.; O’Callaghan, Tom F.; Zheng, Jiamin; Zhang, Lun; Mandal, Rupasri; Hennessy, Deirdre; Fenelon, Mark; Wishart, David S.; Kelly, Alan L.; McCarthy, Noel; et al. (MDPI AG, 2020-05-04)
    The influence of diet on the water-soluble vitamin composition of skim milk powder and whey protein ingredients produced from the milk of cows fed pasture or concentrate-based diets was examined. Fifty-one Holstein-Friesian cows were randomly assigned into three diets (n = 17) consisting of outdoor grazing of perennial ryegrass (GRS), perennial ryegrass/white clover (CLV), or indoor feeding of total mixed ration (TMR) for an entire lactation. Raw mid-lactation milk from each group was processed into skim milk powder and further processed to yield micellar casein whey and acid whey. Sweet whey was also produced by renneting of pasteurised whole milk from each system. The water-soluble vitamin profile of each sample was analysed using a combination of direct injection mass spectrometry and reverse-phase liquid chromatography–mass spectrometry. Vitamin B3 and B3-amide concentrations were significantly higher (p < 0.05) in TMR-derived samples than in those from CLV and GRS, respectively. Vitamin B1, B2, and B7 concentrations were significantly higher in GRS and CLV-derived samples than those from TMR. Significant differences in vitamins B1, B2, and B3-amide were also observed between protein ingredient types. This study indicates that bovine feeding systems have a significant effect on B vitamin composition across a range of protein ingredient types.
  • A standardised static in vitro digestion method suitable for food – an international consensus

    Minekus, M.; Alminger, M.; Alvito, P.; Ballance, S.; Bohn, T.; Bourlieu, C.; Carrière, F.; Boutrou, R.; Corredig, M.; Dupont, D.; et al. (Royal Society of Chemistry (RSC), 2014-04-07)
    Simulated gastro-intestinal digestion is widely employed in many fields of food and nutritional sciences, as conducting human trials are often costly, resource intensive, and ethically disputable. As a consequence, in vitro alternatives that determine endpoints such as the bioaccessibility of nutrients and non-nutrients or the digestibility of macronutrients (e.g. lipids, proteins and carbohydrates) are used for screening and building new hypotheses. Various digestion models have been proposed, often impeding the possibility to compare results across research teams. For example, a large variety of enzymes from different sources such as of porcine, rabbit or human origin have been used, differing in their activity and characterization. Differences in pH, mineral type, ionic strength and digestion time, which alter enzyme activity and other phenomena, may also considerably alter results. Other parameters such as the presence of phospholipids, individual enzymes such as gastric lipase and digestive emulsifiers vs. their mixtures (e.g. pancreatin and bile salts), and the ratio of food bolus to digestive fluids, have also been discussed at length. In the present consensus paper, within the COST Infogest network, we propose a general standardised and practical static digestion method based on physiologically relevant conditions that can be applied for various endpoints, which may be amended to accommodate further specific requirements. A frameset of parameters including the oral, gastric and small intestinal digestion are outlined and their relevance discussed in relation to available in vivo data and enzymes. This consensus paper will give a detailed protocol and a line-by-line, guidance, recommendations and justifications but also limitation of the proposed model. This harmonised static, in vitro digestion method for food should aid the production of more comparable data in the future.
  • Dairy cow feeding system alters the characteristics of low-heat skim milk powder and processability of reconstituted skim milk

    Gulati, Arunima; Hennessy, Deirdre; O'Donovan, Michael; McManus, Jennifer J.; Fenelon, Mark; Guinee, Timothy P.; Department of Agriculture, Food and the Marine; Dairy Levy Trust Co-Operative Society Limited; 11/sf/309 (Elsevier for American Dairy Science Association, 2019-08-01)
    Low-heat skim milk powder (LHSMP) was manufactured on 3 separate occasions in mid lactation (ML, July 4–20) and late lactation (LL, September 27 to October 7) from bulk milk of 3 spring-calving dairy herds on different feeding systems: grazing on perennial ryegrass (Lolium perenne L.) pasture (GRO), grazing on perennial ryegrass and white clover (Trifolium repens L.) pasture (GRC), and housed indoors and offered total mixed ration (TMR). The resultant powders (GRO-SMP, GRC-SMP, and TMR-SMP) were evaluated for composition and color and for the compositional, physicochemical, and processing characteristics of the reconstituted skim milk (RSM) prepared by dispersing the powders to 10% (wt/wt) in water. Feeding system significantly affected the contents of protein and lactose, the elemental composition, and the color of the LHSMP, as well as the rennet gelation properties of the RSM. The GRO and GRC powders had a higher protein content; lower levels of lactose, iodine, and selenium; and a more yellow-green color (lower a* and higher b* color coordinates) than TMR powder. On reconstitution, the GRO-RSM had higher concentrations of protein, casein, and ionic calcium, and lower concentrations of lactose and nonprotein nitrogen (% of total N). It also produced rennet gels with a higher storage modulus (G′) than the corresponding TMR-RSM. These effects were observed over the combined ML and LL period but varied somewhat during the separate ML and LL periods. Otherwise, feeding system had little or no effect on proportions of individual caseins, concentration of serum casein, casein micelle size, casein hydration, heat coagulation time, or ethanol stability of the RSM at pH 6.2 to 7.2, or on the water-holding capacity, viscosity, and flow behavior of stirred yogurt prepared by starter-induced acidification of RSM. The differences in the functionality of the LHSMP may be of greater or lesser importance depending on the application and the conditions applied during the processing of the RSM.

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