Now showing items 21-40 of 415

    • Review of ultrasound combinations with hybrid and innovative techniques for extraction and processing of food and natural products

      Khadhraoui, B.; Ummat, V.; Tiwari, B.K.; Fabiano-Tixier, A.S.; Chemat, F.; Ireland's European Structural and Investment Programmes; Science Foundation Ireland; European Regional Development Fund; 16/RC/3889 (Elsevier, 2021-08)
      Ultrasound has a significant effect on the rate of various processes in food, perfume, cosmetic, pharmaceutical, bio-fuel, materials, or fine chemical industries, despite some shortcomings. Combination with other conventional or innovative techniques can overcome these limitations, enhance energy, momentum and mass transfer, and has been successfully demonstrated in many recent studies. Various ultrasound combined hybrid and innovative techniques are systematically summarized in this review for the first time. Ultrasound can be combined with diverse conventional techniques including Soxhlet, Clevenger, enzyme, hydrotropes, ionic liquids, Deep Eutectic Solvents (DES) or Natural Deep Eutectic Solvents (NADES), to enhance mixing and micro-mixing, reduced thermal and concentration gradients, and selective extraction. Moreover, combinations of ultrasound with other innovative techniques such as microwave, extrusion, supercritical fluid, subcritical and pressure liquids, Instant controlled pressure drop (DIC), Pulsed Electric Field (PEF), Ultra-Violet (UV) or Infra-Red (IR) radiations, Counter-current chromatography (CCC), or centrifugal partition chromatographs (CPC) can enable reduced equipment size, faster response to process control, faster start-up, increased production, and elimination of process steps. The theories and applications of these ultrasound combined hybrid and innovative techniques as well as their advantages and limitations are compared, and further perspectives are proposed. This review provides new insights into advances in ultrasound combined techniques and their application at research, educational, and industrial level in modern food and plant-based chemistry.
    • Effect of high-temperature treatment of milk and whey protein denaturation on the properties of rennet–curd cheese: A review

      Guinee, Timothy P. (Elsevier, 2021-10)
      High temperature treatment of milk (HTT) at temperatures (e.g., 75–100 °C for 1–10 min) higher than those used in conventional pasteurisation (72 °C for 15–30 s) has been used in the manufacture of rennet-curd cheeses to increase the recovery of whey protein, enhance cheese yield, and/or improve the texture of reduced-fat cheese. HTT results in denaturation and interaction of denatured whey proteins with κ-casein. The denatured whey protein/κ-casein complexes remain with the para-κ-casein micelle following rennet hydrolysis, and impede its fusion during gelation and syneresis of the resultant curd, to a degree that increases with severity of HTT. Consequently, cheese from HTT-milk has higher contents of moisture and denatured whey protein, is softer, and has inferior melting properties on baking or grilling. The effects of HTT can be partially mitigated by alteration of cheesemaking parameters to normalise cheese composition, and/or addition of exogenous proteinases to improve melting properties.
    • INFOGEST inter-laboratory recommendations for assaying gastric and pancreatic lipases activities prior to in vitro digestion studies

      Grundy, Myriam M.L.; Abrahamse, Evan; Almgren, Annette; Alminger, Marie; Andres, Ana; Ariëns, Renata M.C.; Bastiaan-Net, Shanna; Bourlieu-Lacanal, Claire; Brodkorb, Andre; Bronze, Maria R.; et al. (Elsevier, 2021-07)
      In vitro digestion studies often use animal digestive enzyme extracts as substitutes of human gastric and pancreatic secretions. Pancreatin from porcine origin is thus commonly used to provide relevant pancreatic enzymes such as proteases, amylase and lipase. Rabbit gastric extracts (RGE) have been recently introduced to provide gastric lipase in addition to pepsin. Before preparing simulated gastric and pancreatic extracts with targeted enzyme activities as described in in vitro digestion protocols, it is important to determine the activities of enzyme preparations using validated methods. The purpose of this inter-laboratory study within the INFOGEST network was to test the repeatability and reproducibility of lipase assays using the pH-stat technique for measuring the activities of gastric and pancreatic lipases from various sources. Twenty-one laboratories having different pH-stat devices received the same protocol with identical batches of RGE and two pancreatin sources. Lipase assays were performed using tributyrin as a substrate and three different amounts (50, 100 and 200 µg) of each enzyme preparation. The repeatability results within individual laboratories were satisfactory with coefficients of variation (CVs) ranging from 4 to 8% regardless of the enzyme amount tested. However, the inter-laboratory variability was high (CV > 15%) compared to existing standards for bioanalytical assays. We identified and weighted the contributions to inter-laboratory variability of several parameters associated with the various pH-stat equipment used in this study (e.g. reaction vessel volume and shape, stirring mode and rate, burette volume for the automated delivery of sodium hydroxide). Based on this, we established recommendations for improving the reproducibility of lipase assays using the pH-stat technique. Defining accurate and complete recommendations on how to correctly quantify activity levels of enzyme preparations is a gateway to promising comparison of in vitro data obtained from different laboratories following the same in vitro digestion protocol.
    • Quantification of calcium in infant formula using laser-induced breakdown spectroscopy (LIBS), Fourier transform mid-infrared (FT-IR) and Raman spectroscopy combined with chemometrics including data fusion

      Zhao, Ming; Markiewicz-Keszycka, Maria; Beattie, Renwick J.; Casado-Gavalda, Maria P.; Cama-Moncunill, Xavier; O'Donnell, Colm P.; Cullen, Patrick J.; Sullivan, Carl; Department of Agriculture, Food and the Marine, Ireland; 14/F/866 (Elsevier, 2020-08)
      Laser-induced breakdown spectroscopy (LIBS), Fourier transform mid-infrared (FT-IR) and Raman spectroscopy combined with chemometrics were investigated to quantify calcium (Ca) content in infant formula powder (INF). INF samples (n = 51) with calcium content levels (ca. 6.5–30 mg Ca/100 kJ) were prepared in accordance with the guidelines of Commission Directive 2006/125/EC. Atomic absorption spectroscopy (AAS) was used as the reference method for Ca content determination. To predict Ca content in INF samples, partial least squares regression (PLSR) models that developed based on LIBS, Raman and FT-IR spectral data, respectively. The model developed using LIBS data achieved the best performance for the quantification of Ca content in INF (R2 (cross-validation (CV))-0.99, RMSECV-0.29 mg/g; R2 (prediction (P))-1, RMSEP-0.63 mg/g). PLSR models that developed based on data fusion of Raman and FT-IR spectral features obtained the second best performance (R2CV-0.97, RMSECV-0.38 mg/g; R2P-0.97, RMSEP-0.36 mg/g). This study demonstrated the potential of LIBS, FT-IR and Raman spectroscopy to accurately quantify Ca content in INF.
    • Seasonal variations in the functional performance of industrial low-moisture part-skim mozzarella over a 1.5-year period

      To, C.M.; Vermeir, L.; Kerkaert, B.; Van Gaver, D.; Van der Meeren, P.; Guinee, T.P.; Flemish Agency for Innovation & Entrepreneurship; HBC.2017.0297 (Elsevier, 2020-12-31)
      Seventy-five blocks of low-moisture part-skim mozzarella cheese were procured from an industrial cheese plant, and the relationships between the physicochemical and functional properties were evaluated during refrigerated storage. In total, cheeses were obtained from 1 cheese vat on 7 different production dates, at 2 to 4 monthly intervals, over a 1.5-yr period; all cheeses were made using a standard recipe. The cheeses were held at 4°C for 0, 1, 2, 4, 8, 16, or 32 d and assayed for composition, primary proteolysis, serum distribution, texture profile analysis, heat-induced changes in viscoelastic behavior, cheese extensibility, and melt characteristics. The results demonstrated a substantial increase in serum uptake by the calcium-phosphate para-casein matrix between 1 and 16 d of storage with a concomitant improvement in the functional performance of the cheese. Extending the storage time to 32 d resulted in further changes in the functional quality, concurrent with ongoing increases in protein hydration and primary proteolysis. Differences in the measured characteristics between the cheeses obtained on different sampling occasions were evident. Principal component analysis separated the cheeses based on their variance in functional performance, which was found to be correlated mainly with the calcium content of the cheese. The results indicate that the manufacturing process should be tightly controlled to minimize variation in calcium content and enhance the quality consistency of the cheese.
    • Alternative protocols for the production of more sustainable agar-based extracts from Gelidium sesquipedale

      Martínez-Sanz, Marta; Gomez-Barrio, Laura Pilar; Zhao, Ming; Tiwari, Brijesh; Knutsen, Svein Halvor; Ballance, Simon; Zobel, Hanne Kristine; Nilsson, Anna Ekman; Krewer, Christoffer; Östergren, Karin; et al. (Elsevier, 2021-05)
      Agar-based extracts from Gelidium sesquipedale were obtained by applying a conventional hot water treatment and alternative ultrasound- and microwave-assisted methods, with and without the application of an alkaline pre-treatment. The alkaline pre-treatment produced refined extracts with higher purity; however, extraction yields increased from 2–5% to 7–19% by omitting this step. In particular, the ultrasound-assisted extraction allowed reducing 4-fold the extraction time, while keeping constant or even increasing the yield (up to 19% for the 1 h extraction) with respect to the conventional protocol. Interestingly, the presence of proteins and polyphenols conferred the semi-refined extracts a relatively high antioxidant capacity (19–24 μmol TE/g extract). The refined extract produced by the standard protocol formed the strongest hydrogels (>1000 g/cm2). On the other hand, the semi-refined extracts produced by the alternative protocols formed slightly stronger hydrogels (337–438 g/cm2) than the refined counterparts (224–311 g/cm2), due to their greater molecular weights of the former ones. LCA assessment showed lower global warming potential for the semi-refined extracts, especially the ultrasound-assisted extraction, hence highlighting the potential of this method to produce more sustainable agar-based extracts for food-related applications.
    • An evaluation of sonication pretreatment for enhancing saccharification of brewers' spent grain

      Hassan, Shady S.; Ravindran, Rajeev; Jaiswal, Swarna; Tiwari, Brijesh K.; Williams, Gwilym A.; Jaiswal, Amit K.; Science Foundation Ireland; TU Dublin-City Campus; 16/RC/3889 (Elsevier, 2020-03-15)
      This paper deals with the investigation of ultrasound (US) pretreatment of brewer’s spent grain (BSG) as a means of releasing fermentable sugars, and the subsequent production of ethanol from this lignocellulosic biomass. Using response surface methodology (RSM), the influence of US power, time, temperature and biomass loading on fermentable sugar yield from BSG was studied. The optimal conditions were found to be 20% US power, 60 min, 26.3 °C, and 17.3% w/v of biomass in water. Under these conditions, an approximate 2.1-fold increase in reducing sugar yield (325 ± 6 mg/g of biomass) was achieved, relative to untreated BSG (151.1 ± 10 mg/g of biomass). In contrast to acid or alkaline pretreatment approaches, the use of water obviated the need for neutralization for the recovery of sugars. The characterization of native and pretreated BSG was performed by HPLC, FTIR, SEM and DSC. Fermentation studies using S. cerevisiae growing on pretreated BSG resulted in a conversion of 66% of the total sugar content ininto ethanol with an ethanol content of 17.73 ± 2 g/ 100 g of pretreated BSG. These results suggest that ultrasound pretreatment is a promising technology for increased valorization of BSG as a feedstock for production of bioethanol, and points ton the need for further work in this area.
    • The effect of storage conditions on the composition and functional properties of blended bulk tank milk

      O'Connell, A.; Kelly, A.L.; Tobin, J.; Ruegg, P.L.; Gleeson, D. (Elsevier, 2017-02-28)
      The objective of this study was to investigate the effects of storage temperature and duration on the composition and functional properties of bulk tank milk when fresh milk was added to the bulk tank twice daily. The bulk tank milk temperature was set at each of 3 temperatures (2, 4, and 6°C) in each of 3 tanks on 2 occasions during two 6-wk periods. Period 1 was undertaken in August and September when all cows were in mid lactation, and period 2 was undertaken in October and November when all cows were in late lactation. Bulk tank milk stored at the 3 temperatures was sampled at 24-h intervals during storage periods of 0 to 96 h. Compositional parameters were measured for all bulk tank milk samples, including gross composition and quantification of nitrogen compounds, casein fractions, free amino acids, and Ca and P contents. The somatic cell count, heat stability, titratable acidity, and rennetability of bulk tank milk samples were also assessed. Almost all parameters differed between mid and late lactation; however, the interaction between lactation, storage temperature, and storage duration was significant for only 3 parameters: protein content and concentrations of free cysteic acid and free glutamic acid. The interaction between storage temperature and storage time was not significant for any parameter measured, and temperature had no effect on any parameter except lysine: lysine content was higher at 6°C than at 2°C. During 96 h of storage, the concentrations of some free amino acids (glutamic acid, lysine, and arginine) increased, which may indicate proteolytic activity during storage. Between 0 and 96 h, minimal deterioration was observed in functional properties (rennet coagulation time, curd firmness, and heat stability), which was most likely due to the dissociation of β-casein from the casein micelle, which can be reversed upon pasteurization. Thus, this study suggests that blended milk can be stored for up to 96 h at temperatures between 2°C and 6°C with little effect on its composition or functional properties.
    • Chemical modification of citrus pectin: Structural, physical and rheologial implications

      Fracasso, Aline Francielle; Perussello, Camila Augusto; Carpiné, Danielle; Petkowicz, Carmen Lúcia de Oliveira; Haminiuk, Charles Windson Isidoro; CAPES (Coordination for the Improvement of Higher Education Personnel); Graduate Program in Food Engineering (Federal University of Paraná, Curitiba, Brazil); National Council for Scientific and Technological Development; Araucaria Foundation; UFPR (Department of Biochemistry and Molecular Biology); et al. (Elsevier, 2018-04)
      The present study aimed to investigate the physical, structural and rheological modifications caused by the chemical modification process of citrus pectin. Therefore, three commercial citrus pectins with different degree of esterification were chemically modified by sequential alkali and acidic hydrolytic process to produce modified citrus pectins (MCP) with special properties. The molar mass (Mw), degree of esterification (DE), monosaccharide composition, 13C NMR spectra, homogeneity, morphology (SEM) and rheological behavior of both native and modified citrus pectins (MCP) were investigated. The chemical modification reduced the acid uronic content (up to 28.3%) and molar mass (up to 29.98%), however, showed little influence on the degree of esterification of native pectins. Modified citrus pectins presented higher amounts of neutral monosaccharides, mainly galactose, arabinose and rhamnose, typical of the Ramnogalacturonana-I (RG-I) region. Rheological tests indicated that the native and modified citrus pectins presented pseudoplastic behavior, however, the MCP samples were less viscous, compared to the native ones. Modified samples presented better dissolution in water and less strong gels, with good stability during oscillatory shearing at 25 °C. This study aims to better understand the implications that chemical modifications may impose on the structure of citrus pectins.
    • Effect of milk centrifugation and incorporation of high-heat-treated centrifugate on the composition, texture, and ripening characteristics of Maasdam cheese

      Lamichhane, Prabin; Kelly, Alan L.; Sheehan, Jeremiah J.; Dairy Levy Trust (Dublin, Ireland); Teagasc Walsh Fellowship program; Ornua (Dubin, Ireland); RMIS6259 (Elsevier, 2018-07-31)
      This study investigated the effect of centrifugation (9,000 × g, 50°C, flow rate = 1,000 L/h), as well as the incorporation of high-heat-treated (HHT) centrifugate into cheese milk on the composition, texture, and ripening characteristics of Maasdam cheese. Neither centrifugation nor incorporation of HHT centrifugate into cheese milk had a pronounced effect on the compositional parameters of any experimental cheeses, except for moisture and moisture in nonfat substance (MNFS) levels. Incorporation of HHT centrifugate at a rate of 6 to 10% of the total milk weight into centrifuged milk increased the level of denatured whey protein in the cheese milk and also increased the level of MNFS in the resultant cheese compared with cheeses made from centrifuged milk and control cheeses; moreover, cheese made from centrifuged milk had ∼3% higher moisture content on average than control cheeses. Centrifugation of cheese milk reduced the somatic cell count by ∼95% relative to the somatic cell count in raw milk. Neither centrifugation nor incorporation of HHT centrifugate into cheese milk had a significant effect on age-related changes in pH, lactate content, and levels of primary and secondary proteolysis. However, the value for hardness was significantly lower for cheeses made from milk containing HHT centrifugate than for other experimental cheese types. Overall, centrifugation appeared to have little effect on composition, texture, and ripening characteristics of Maasdam cheese. However, care should be taken when incorporating HHT centrifugate into cheese milk, because such practices can influence the level of moisture, MNFS, and texture (particularly hardness) of resultant cheeses. Such differences may have the potential to influence subsequent eye development characteristic, although no definitive trends were observed in the present study and further research on this is recommended.
    • Addition of sodium caseinate to skim milk increases nonsedimentable casein and causes significant changes in rennet-induced gelation, heat stability, and ethanol stability

      Lin, Yingchen; Kelly, Alan L.; O'Mahony, James A.; Guinee, Timothy P.; Dairy Levy Trust (Elsevier, 2017-02-28)
      The protein content of skim milk was increased from 3.3 to 4.1% (wt/wt) by the addition of a blend of skim milk powder and sodium caseinate (NaCas), in which the weight ratio of skim milk powder to NaCas was varied from 0.8:0.0 to 0.0:0.8. Addition of NaCas increased the levels of nonsedimentable casein (from ∼6 to 18% of total casein) and calcium (from ∼36 to 43% of total calcium) and reduced the turbidity of the fortified milk, to a degree depending on level of NaCas added. Rennet gelation was adversely affected by the addition of NaCas at 0.2% (wt/wt) and completely inhibited at NaCas ≥0.4% (wt/wt). Rennet-induced hydrolysis was not affected by added NaCas. The proportion of total casein that was nonsedimentable on centrifugation (3,000 × g, 1 h, 25°C) of the rennet-treated milk after incubation for 1 h at 31°C increased significantly on addition of NaCas at ≥0.4% (wt/wt). Heat stability in the pH range 6.7 to 7.2 and ethanol stability at pH 6.4 were enhanced by the addition of NaCas. It is suggested that the negative effect of NaCas on rennet gelation is due to the increase in nonsedimentable casein, which upon hydrolysis by chymosin forms into small nonsedimentable particles that physically come between, and impede the aggregation of, rennet-altered para-casein micelles, and thereby inhibit the development of a gel network.
    • Temporal alterations in the bovine buttermilk glycome from parturition to milk maturation

      Ross, Sarah A.; Gerlach, Jared Q.; Gill, Satbir K.; Lane, Jonathan A.; Kilcoyne, Michelle; Hickey, Rita M.; Joshi, Lokesh; Department of Agriculture and Food, Ireland; Teagasc Walsh Fellowship; Science Foundation Ireland; et al. (Elsevier, 2016-11-15)
      The bovine milk fat globule membrane (MFGM) has many associated biological activities, many of which are linked with specific carbohydrate structures of MFGM glycoconjugates. Bovine buttermilk is a commercially viable source of MFGM and is an under-valued by-product of butter making. However, the changes in buttermilk glycosylation over the course of lactation have not been extensively investigated. In this study, buttermilk was generated from three individual multiparous cows at 13 time points over the first three months of lactation. Buttermilk glycosylation was profiled using lectin microarrays and lectin blotting. Suggested differences in glycosylation, including N-glycosylation, sialylation and fucosylation, were observed between early and late time points and between individual animals. Overall, these data suggest temporal changes in the glycosylation of buttermilk proteins which may have an important impact on commercial isolation of glycosylated ingredients.
    • Effect of varying the salt and fat content in Cheddar cheese on aspects of the performance of a commercial starter culture preparation during ripening

      Yanachkina, Palina; McCarthy, Catherine; Guinee, Tim; Wilkinson, Martin; Department of Agriculture, Fisheries and Food; 10/RD/CheeseBoard2015/TMFRC/704 (Elsevier, 2016-05-02)
      Production of healthier reduced-fat and reduced-salt cheeses requires careful selection of starter bacteria, as any substantial alterations to cheese composition may prompt changes in the overall performance of starters during cheese ripening. Therefore, it is important to assess the effect of compositional alterations on the individual strain response during cheese ripening for each optimised cheese matrix. In the current study, the effect of varying fat and salt levels in Cheddar cheese on the performance of a commercial Lactococcus lactis culture preparation, containing one L. lactis subsp. lactis strain and one L. lactis subsp. cremoris strain was investigated. Compositional variations in fat or salt levels did not affect overall starter viability, yet reduction of fat by 50% significantly delayed non-starter lactic acid bacteria (NSLAB) populations at the initial ripening period. In comparison to starter viability, starter autolysis, as measured by release of intracellular lactate dehydrogenase (LDH) or post-proline dipeptidyl aminopeptidase (Pep X) into cheese juices, decreased significantly with lower salt addition levels in full-fat Cheddar. Conversely, reducing fat content of cheese resulted in a significantly higher release of intracellular Pep X, and to a lesser extent intracellular LDH, into juices over ripening. Flow cytometry (FCM) indicated that the permeabilised and dead cell sub-populations were generally lower in juices from cheeses with reduced salt content, however no significant differences were observed between different salt and fat treatments. Interestingly, fat reductions by 30 and 50% in cheeses with reduced or half added salt contents appeared to balance out the effect of salt, and enhanced cell permeabilisation, cell death, and also cell autolysis in these variants.Overall, this study has highlighted that alterations in both salt and fat levels in cheese influence certain aspects of starter performance during ripening, including autolysis, permeabilisation, and intracellular enzyme release. However, it may be possible to reduce the fat and salt content of Cheddar cheese by 30 or 50%, respectively, without largely altering permeabilised and dead cell sub-populations and, in turn, the amount of released intracellular Pep X activity, such that these performance parameters are similar to those observed for control full-fat, full-salt Cheddar cheese.
    • Influence of emulsifier type on the spray-drying properties of model infant formula emulsions

      Drapala, Kamil P.; Auty, Mark A.E.; Mulvihill, Daniel M.; O'Mahony, James A.; Irish Department of Agriculture, Food and the Marine; FIRM; 10/RD/Optihydro/UCC/702 (Elsevier, 2017-08-31)
      The objective of this study was to compare the drying performance and physicochemical properties of model infant formula (IF) emulsions containing 43, 96 and 192 g L−1 protein, oil and maltodextrin (MD), respectively, prepared using different emulsifier systems. Emulsions were stabilised using either whey protein isolate (WPI), whey protein hydrolysate (WPH; DH 8%), WPH + CITREM (9 g L−1), WPH + lecithin (5 g L−1) or WPH conjugated with maltodextrin (DE 12) (WPH-MD). Homogenised emulsions had 32% solids content and oil globules with mean volume diameter <1 μm. Powders were produced by spray-drying with inlet and outlet temperatures of 170 and 90 °C, respectively, to an average final moisture content of 1.3%. The extent of powder build-up on the dryer wall increased in the order; WPH- MD << WPH ≤ WPI < WPH + LEC ≤ WPH + CIT. The same trend was observed for the extent of spontaneous primary powder agglomeration, as confirmed by particle size distribution profiles and scanning electron micrographs, where the WPH-MD and WPH + CIT powders displayed the least and greatest extent of agglomeration, respectively. Analysis of elemental surface composition of the powders showed that surface fat, protein and carbohydrate decreased in the order; WPH + CIT > WPH + LEC > WPH > WPH- MD > WPI, WPI > WPH > WPH- MD > WPH + LEC > WPH + CIT and WPH- MD > WPI > WPH > WPH + LEC > WPH + CIT, respectively. Additionally, differences in wettability, surface topography and oil globule distribution within the powder matrix and in reconstituted powders were linked to the emulsifier system used. Inclusion of the WPH-MD conjugate in the formulation of IF powder significantly improved drying behaviour and physicochemical properties of the resultant powder, as evidenced by lowest powder build-up during drying and greatest emulsion quality on reconstitution, compared to the other model formula systems.
    • Rehydration behaviours of high protein dairy powders: The influence of agglomeration on wettability, dispersibility and solubility

      Ji, Junfu; Fitzpatrick, John; Cronin, Kevin; Maguire, Pierce; Zhang, Hongzhou; Miao, Song; Department of Agriculture and Food and Marine Ireland; 11-F-001 (Elsevier, 2016-07-31)
      Five common high protein dairy powders and their agglomerates produced by fluidised bed granulation were evaluated and compared for their rehydration characteristics in this study. Wettability of powders was measured by immersion wetting time, capillary rise wetting and contact angles methods, while dispersion and solubilisation processes were quantified by the change of particle size and the sediment height after centrifugation. The results showed that these high protein dairy powders generally had poor wettability, especially for whey protein isolate and the caseinates, which formed an impermeable layer separating the water surface and powders just after they contacted the water. However, the casein-micellar dominant powders exhibited prolonged dispersion due to strong interactions inside the micellar structures. The agglomerates with large particle size and high porosity are expected to exhibit increased wettability. However, agglomeration only caused the external structural modification and thus is difficult to accelerate the dispersion process of micellar casein, which can be explained by the milk protein isolate rehydration mechanism. The micellar structure inhibits the release of materials into surrounding liquid phase, which is mainly responsible for the extended rehydration time.
    • The structural modification and rehydration behaviours of milk protein isolate powders: The effect of granule growth in the high shear granulation process

      Ji, Junfu; Cronin, Kevin; Fitzpatrick, John; Maguire, Pierce; Zhang, Hongzhou; Miao, Song; Food Institutional Research Measure (FIRM) of the Department of Agriculture and Food and Marine Ireland; 11-F-001 (Elsevier, 2016-11)
      The effects of granule growth in high shear granulation on the structures and rehydration abilities of milk protein powders were investigated. In this study, milk protein isolate, as a model powder, was agglomerated in a high shear granulator. The formed granules with different sizes were used to compare the densities, granule shapes and subsequently the wettability, dispersibility and solubility. It is found that the small nuclei showed the most compacted structures. Then the primary agglomerates coalesced to create irregular secondary structures with lower density and higher porosity until the final agglomerates formed. The densely packed structures allowed the granules to be more easily wetted by water. The large granules showed quicker release of materials into water until reaching a critical size, where more mechanical energy is potentially required for further granule break down. All the agglomerated MPI granules solubilised much more slowly than the standard MPI powder.
    • Flavor release from spray-dried amorphous matrix: Effect of lactose content and water plasticization

      Li, Runjing; Roos, Yrjö H.; Miao, Song; Department of Agriculture, Food and Marine, Ireland,; 11-F-001 (Elsevier, 2016-08-31)
      Glass-forming carbohydrates are widely used as matrix for encapsulation of nutrients and bioactive compounds. In this study, encapsulation systems with lactose/whey protein isolate (WPI) mixtures (4:1, 1:1, and 1:4), or WPI as wall materials and ethyl butyrate as core material were prepared by spray drying. The effects of lactose content and water plasticization on encapsulation efficiency and flavor release were investigated. Wall material consisting of lactose/WPI (4:1) mixture had significantly (P<0.05) higher encapsulation efficiency. The flavor retention in powders did not have significant decrease with equilibration at 0.33 aw, while it was dramatically decreased at 0.54 aw and 0.65 aw as a result of lactose crystallisation. Mechanical property study showed that the molecular mobility and free volume of encapsulation systems with higher lactose content increased more significantly with increasing water content, which accelerated the diffusion of flavor molecules. Those results may use in the assessment of protection and release characteristics of flavor components in formulated systems.
    • Carotenoid stability in high total solid spray dried emulsions with gum Arabic layered interface and trehalose–WPI composites as wall materials

      Lim, Aaron S.L.; Burdikova, Zuzana; Sheehan, Jeremiah J.; Roos, Yrjö H.; Department of Agriculture, Food, and the Marine, Ireland; project11-F-001 (Elsevier, 2016-04-30)
      The present study investigated the ability of spray dried single layer (SL) and layer-by-layer (LBL) high total solid emulsions with carbohydrate (trehalose) and non-carbohydrate (WPI) solids to stabilize carotenoids upon storage at 35°C, 50°C, and 65°C. Carotenoid loss followed first order loss kinetics, and increased with increasing storage temperature. Rapid initial first order loss followed by a second, less rapid first order loss was observed. Storage of the systems above the Tg reduced carotenoid loss in the initial first order loss. The loss of carotenoids in LBL system was more temperature dependent initially but SL system was more temperature dependent in the second first order loss step. LBL system showed slower loss rate of carotenoids in the initial first order loss step and at 65°C in the second step. Carotenoid retention was significantly higher in LBL system upon storage at 65°C. Industrial relevanceAlthough layer-by-layer (LBL) technique has been known to produce emulsions with better stability towards environmental stresses, few have reported the application of LBL technique using systems with high total solids. The application of LBL technique on emulsion with high total solids and subsequent spray-drying of the emulsion in this manuscript will provide useful information to the food and pharmaceutical industries. The possibility to spray-dry such systems with high total solids producing high quality powders would be feasible to the industry as it greatly reduces production cost. The present study also reports on the carotenoid loss kinetics of dehydrated concentrated systems with carbohydrate and non-carbohydrate mixtures as wall materials and compares the ability of single layer (SL) and LBL systems in preventing the loss of the encapsulated carotenoids.
    • Physical and mechanical properties of lactose/WPI mixtures: Effect of pre-crystallisation

      Li, Runjing; Roos, Yrjö H.; Miao, Song; Department of Agriculture, Food and Marine, Ireland; 11-F-001 (Elsevier BV, 2016-05)
      This study investigated the physical and mechanical properties of spray-dried lactose/whey protein isolate (WPI) (4:1) mixtures with different contents of α-lactose monohydrate (1.0%, 11.2%, 29.2%, and 46.8%, w/w). Particle size of samples with 11.2%, 29.2%, and 46.8% crystallinity was significantly (P < 0.05) larger compared with the sample with 1.0% crystallinity. The presence of less than 46.8% crystalline lactose in lactose/WPI mixtures had only a minor effect on water sorption behaviour at aw 0.11–0.44, whereas samples with higher crystallinity had higher stable water content after showing lactose crystallisation. Moreover, samples with lower crystallinity showed higher initial sorption rates. Increasing the amount of crystalline lactose had no significant influence on the glass transition temperature and the initial crystallisation temperatures at aw 0.11–0.44. Furthermore, dairy powders with higher crystallinity had higher stiffness and water plasticisation showed a stronger effect on the structural relaxation of dairy powders with lower crystallinity.
    • Health Implications of Beef Intramuscular Fat Consumption

      Troy, Declan J.; Tiwari, Brijesh K.; Joo, Seon-Tea (Korean Society for Food Science of Animal Resources, 2016-10-31)
      Despite several issues in relation to human health, beef is still a most popular meat product among large section of society due to the presence of high quality protein and other nutrients. The current paper reviews numerous studies that provide nutritional profiles and health implications of high marbled beef consumption. In relation to lipid content of beef, intramuscular fat contains high level of PUFA and MUFA compared to other beef fat. Level and composition of intramuscular fat varies depending on breed and feeding regime. Literature suggests that the marbling is more complex than the development of subcutaneous fat and marbling not only provides good fatty acids but also contributes to the higher eating quality of beef. Finally, the current work emphasize that meat plays a pivotal role in nutritious diets, high quality marbled beef is not only of excellent eating quality but also contain more beneficial fatty acids.