Effect of physico-chemical conditions and operating parameters on flux and retention of different components in ultrafiltration and nanofiltration fractionation of sweet whey

Tässä väitöstutkimuksessa tutkittiin fysikaaliskemiallisten olosuhteiden ja toimintaparametrien vaikutusta juustoheran fraktiointiin. Kirjallisuusosassa on käsitelty heran ympäristövaikutusta, heran hyödyntämistä ja heran käsittelyä kalvotekniikalla. Kokeellinen osa on jaettu kahteen osaan, joista ensimmäinen käsittelee ultrasuodatusta ja toinen nanosuodatusta juustoheran fraktioinnissa. Ultrasuodatuskalvon valinta tehtiin perustuen kalvon cut-off lukuun, joka oli määritetty polyetyleeniglykoliliuoksilla olosuhteissa, joissa konsentraatiopolariosaatioei häiritse mittausta. Kriittisen vuon konseptia käytettiin sopivan proteiinikonsentraation löytämiseksi ultrasuodatuskokeisiin, koska heraproteiinit ovat tunnetusti kalvoa likaavia aineita. Ultrasuodatuskokeissa tutkittiin heran eri komponenttien suodattumista kalvon läpi ja siihen vaikuttavia ominaisuuksia. Herapermeaattien peptidifraktiot analysoitiin kokoekskluusiokromatografialla ja MALDI-TOF massaspektrometrillä. Kokeissa käytettävien nanosuodatuskalvojen keskimääräinen huokoskoko analysoitiin neutraaleilla liukoisilla aineilla ja zeta-potentiaalit virtauspotentiaalimittauksilla. Aminohappoja käytettiin malliaineina tutkittaessa huokoskoon ja varauksen merkitystä erotuksessa. Aminohappojen retentioon vaikuttivat pH ja liuoksen ionivahvuus sekä molekyylien väliset vuorovaikutukset. Heran ultrasuodatuksessa tuotettu permeaatti, joka sisälsi pieniä peptidejä, laktoosia ja suoloja, nanosuodatettiin happamassa ja emäksisessä pH:ssa. Emäksisissä oloissa tehdyssä nanosuodatuksessa foulaantumista tapahtui vähemmän ja permeaattivuo oli parempi. Emäksisissä oloissa myös selektiivisyys laktoosin erotuksessa peptideistä oli parempi verrattuna selektiivisyyteen happamissa oloissa.

Recovery of lactoferrin and lactoperoxidase from sweet whey using colloidal gas aphrons (CGAs) generated from an anionic surfactant, AOT

The recovery of lactoferrin and lactoperoxidase from sweet whey was studied using colloidal gas aphrons (CGAs), which are surfactant-stabilized microbubbles (10-100 mum). CGAs are generated by intense stirring (8000 rpm for 10 min) of the anionic surfactant AOT (sodium bis-2-ethylhexyl sulfosuccinate). A volume of CGAs (10-30 mL) is mixed with a given volume of whey (1 - 10 mL), and the mixture is allowed to separate into two phases: the aphron (top) phase and the liquid (bottom) phase. Each of the phases is analyzed by SDS-PAGE and surfactant colorimetric assay. A statistical experimental design has been developed to assess the effect of different process parameters including pH, ionic strength, the concentration of surfactant in the CGAs generating solution, the volume of CGAs and the volume of whey on separation efficiency. As expected pH, ionic strength and the volume of whey (i.e. the amount of total protein in the starting material) are the main factors influencing the partitioning of the Lf(.)Lp fraction into the aphron phase. Moreover, it has been demonstrated that best separation performance was achieved at pH = 4 and ionic strength = 0.1 mol/L i.e., with conditions favoring electrostatic interactions between target proteins and CGAs (recovery was 90% and the concentration of lactoferrin and lactoperoxidase in the aphron phase was 25 times higher than that in the liquid phase), whereas conditions favoring hydrophobic interactions (pH close to pI and high ionic strength) led to lower performance. However, under these conditions, as confirmed by zeta potential measurements, the adsorption of both target proteins and contaminant proteins is favored. Thus, low selectivity is achieved at all of the studied conditions. These results confirm the initial hypothesis that CGAs act as ion exchangers and that the selectivity of the process can be manipulated by changing main operating parameters such as type of surfactant, pH and ionic strength.

Selective separation of beta-lactoglobulin from sweet whey using CGAs generated from the cationic surfactant CTAB

The selective separation of whey proteins was studied using colloidal gas aphrons generated from the cationic surfactant cetyl trimethyl ammonium bromide (CTAB). From the titration curves obtained by zeta potential measurements of individual whey proteins, it was expected to selectively adsorb the major whey proteins, i.e., bovine serum albumin, alpha-lactalbumin, and beta-lactoglobulin to the aphrons and elute the remaining proteins (lactoferrin and lactoperoxidase) in the liquid phase. A number of process parameters including pH, ionic strength, and mass ratio of surfactant to protein (M-CTAB/M-TP) were varied in order to evaluate their effect on protein separation. Under optimum conditions (2 mmol/l CTAB, M-CTAB/M-TP = 0.26-0.35, pH 8, and ionic strength = 0.018 mol/l), 80-90% beta-lactoglobulin was removed from the liquid phase as a precipitate, while about 75% lactoferrin and lactoperoxidase, 80% bovine serum albumin, 95% immunoglobulin, and 65% alpha-lactalbumin were recovered in the liquid fraction. Mechanistic studies using zeta potential measurements and fluorescence spectroscopy proved that electrostatic interactions modulate only partially the selectivity of protein separation, as proteins with similar surface charges do not separate to the same extent between the two phases. The selectivity of recovery of beta-lactoglobulin probably occurs in two steps: the first being the selective interaction of the protein with opposite-charged surfactant molecules by means of electrostatic interactions, which leads to denaturation of the protein and subsequent formation and precipitation of the CTAB-beta-lactoglobulin complex. This is followed by the separation of CTAB-beta-lactoglobulin aggregates from the bulk liquid by flotation in the aphron phase. In this way, CGAs act as carriers which facilitate the removal of protein precipitate. (c) 2005 Wiley Periodicals, Inc.

Isolation and recovery of glycomacropeptide from milk whey by means of thermal treatment

During enzymatic process of cheese manufacturing, rennin cleaves κ-casein releasing two fractions: para-κ-casein and glycomacropeptide (GMP), which remains soluble in milk whey. GMP is a peptide with structural particularities such as chain carbohydrates linked to specific threonine residues, to which a great variety of biological activities is attributed. Worldwide cheese production has increased generating high volumes of milk whey that could be efficiently used as an alternative source of high quality peptide or protein in foodstuff formulations. In order to evaluate isolation and recovery on whey GMP by means of thermal treatment (90 °C), 18 samples (2 L each) of sweet whey, resuspended commercial whey (positive control) and acid whey (negative control) were processed. Indirect presence of GMP was verified using chemical tests and PAGE-SDS 15%. At 90 °C treated sweet whey, 14, 20 and 41 kDa bands were observed. These bands may correspond to olygomers of GMP. Peptide recovery showed an average of 1.5 g/L (34.08%). The results indicate that industrial scale GMP production is feasible; however, further research must be carried out for the biological and nutritional evaluation of GMP's incorporation to foodstuff as a supplement.

Production of acid whey hydrolysates applying an integrative process: effect of calcium on process performance

High ionic calcium concentration and the absence of caseinmacropeptides (CMP) in acid whey could influence the production of angiotensin-I-converting enzyme (ACE)-inhibitory hydrolysate and its bioactivity through the application of the integrative process. Therefore, the aim of the present study was to produce a hydrolysate from acid whey applying the integrative process. Process performance was evaluated based on protein adsorption capacity and conversion in relation to ACE-inhibitory activity (ACEi%) and ionic calcium concentration. Hydrolysates with high potency of their biological activity were produced (IC50 = 206-353 μg mL-1). High ionic calcium concentration in acid whey contributed to ACE-inhibitory activity. However, low β-lactoglobulin adsorption and conversion was observed. Optimisation of the resin volume increased the adsorption of β-lactoglobulin significantly but with lower selectivity. The changes in conversion value were not significant even at higher concentration of enzyme. Several ACE inhibitors derived from β-lactoglobulin that were identified before in sweet whey hydrolysates such as, IIAEKT, IIAE, IVTQ, LIVTQ, LIVTQT, LDAQ and LIVT were found. New peptides such as, SNICNI and ECCHGD derived from α-lactalbumin and BSA respectively were identified.

Heran nanosuodatus: raaka-ainekoostumuksen ja prosessiolosuhteiden vaikutus kalvon likaantumiseen

Työssä tutkittiin kalvon likaantumiseen vaikuttavia tekijöitä juoksuteheran nanosuodatuksessa. Tutkimuksessa käytettiin Desal-5 DK kalvoa. Heran nanosuodatukset suoritettiin yhden spiraalimoduulin käsittävää pilot -mittakaavaista suodatuslaitteistoa käyttäen. Työssä selvitettiin suodatettavan heran iän, pastörointilämpötilan, pH:n, suodatuslämpötilan sekäheran sisältämän juustopölyn, lisätyn kalsiumkloridin määrän ja rasvan laadun vaikutusta permeaattivuohon. Jokaista tekijää testattiin kahta eri muuttujaa käyttäen. Työssä tutkittiin myös kahden samanlaisen kalvon välisiä läpäisevyyseroja. Heran pastörointilämpötila, pH ja suodatuslämpötila osoittautuivat kalvon likaantumisen kannalta tärkeimmiksi tekijöiksi heran nanosuodatuksessa. Permeaattivuo oli korkeampi suodatettaessa 74 ºC lämpötilassa pastöroitua heraa, kuin 78 ºC lämpötilassa pastöroitua. Hera suodattui paremmin silloin, kunsen pH oli säädetty 5,8:aan, kuin heran pH:n ollessa säädettynä 5,2:een. Suodatettaessa 18 ºC suodatuslämpötilaan temperoitua heraa havaittiin korkeampi permeaattivuo kuin 12 ºC lämpötilaan termostoitua heraa suodatettaessa. Heran sisältämä pölyn määrä, rasvan laatu ja heran ikä havaittiin tilastollisesti merkityksettömiksi tekijöiksi sekä heran suodattuvuuden, että kalvon puhdistuvuuden kannalta. Kalsiumkloridin lisääminen heraan ennen suodatusta vaikuttivain kalvon suodatuksen jälkeiseen peseytyvyyteen. Kalvo puhdistui paremmin, kun kalsiumkloridia ei oltu lisätty heraan ennen suodatusta. Desal-5 DK kalvojen läpäisevyyseroja tutkittiin suodattamalla glukoosia ja natriumkloridia sisältävää malliaineliuosta kummankin vertailtavan kalvon läpi. Kokeissa havaittiin, että toista nanosuodatuskalvoa käytettäessä mitatut vesivuot olivat jopa 100 % korkeampia kuin vertailukalvoa käytettäessä mitatut. Myös glukoosin kalvolle pidättymisessä havaittiin eroja kalvojen välillä. Syyksi suuriin läpäisevyyseroihin arveltiin riittämätöntä kalvojen esikäsittelyä ennen malliainekokeen suorittamista, joten ei pystytty arvioimaan, oliko kalvojen läpäisevyyksissävalmistusprosessista johtuvia eroja.

Kalvojen vertailu heran nanosuodatuksessa

Työssä verrattiin kaupallisia nanosuodatuskalvoja heran konsentroinnissa. Tutkitut kalvot olivat Desal-5 DK, NF45 ja Koch SR1. NF45-kalvosta tutkittiin kahta eri sukupolven kalvoa. Konsentrointiajoja tehtiin sekä laboratoriomittakaavan levysuotimella että pilot-mittakaavan spiraalimoduulilaitteella. Lisäksi tutkittiin juoksute- ja happoheran konsentrointien eroja. Erityistä huomiota kiinnitettiin permeaattivuon arvoihin konsentroinnissa ja kalvojen suolojen ja laktoosin pidätyskykyyn. NF45-kalvon uuden sukupolven malli osoittautui mittauksissa samankaltaiseksi suolojen ja laktoosin pidätyskyvyltään kuin Desal-5 DK. Koch SR1-kalvo, jonka suolojen ja laktoosin pidätyskyky on Desal-5 DK-kalvoa heikompi, puolestaan vastaa ominaisuuksiltaan NF45 vanhan sukupolven kalvoa. Vanhan sukupolven NF45-kalvon valmistus on loppunut keväällä 2000. Vaihdettaessa vanhan sukupolven NF45-kalvot uuden sukupolven kalvoihin on odotettavissa pienemmät permeaattivuot ja suuremmat suolojen ja laktoosin retentiot kuin aiemmin NF45-kalvolla. Juoksuteheran konsentroinnissa suurimmat permeaattivuot saatiin Koch SR1-kalvolla. Levysuotimella ja spiraalimoduulilla saadaan koostumukseltaan samanlainen juoksuteheratiiviste. Levysuotimella permeaattivuot ovat samalla konsentrointikertoimella suuremmat kuin spiraalimoduulilla. Tämä johtuu spiraalimoduuliin jäävistä kuolleista alueista, joissa ei ole virtausta. Uutta prosessia suunniteltaessa voidaan käyttää laboratoriomittakaavan levysuodinkokokeita, kun halutaan tietoa saatavan tuotteen koostumuksesta. Prosessin tuotantokapasiteetin arvioimiseen tarvitaan pilot-mittakaavan spiraalimoduulikokeita. Happoheratiiviste sisältää enemmän suoloja kuin samalla kalvolla valmistettu juoksuteheratiiviste. Tämä johtuu happoheran juoksuteheraa suuremmasta suolapitoisuudesta. Lisäksi happoheran konsentroinnin permeaattivuo on pienempi kuin juoksuteheran permeaattivuo, sillä happoheran alhainen pH, noin 4,5, vaikuttaa kalvon permeabiliteettiin heikentävästi.

Determinação de GMP e CMP* no leite por métodos espectrofotométrico (ANSM) e cromatográfico (HPLC) - parâmetros metodológicos (*glicomacropeptídeo e caseinomacropeptídeo)

Glycomacropeptide is a glycosilated fraction of bovine kappa-casein that remains soluble when milk is clotted by rennin. Determinations of milk sialic acid content are useful because its concentration reflects the amount of free GMP of milk. In normal milk these amounts are very low, 12 to 16 times lower than in sweet whey. Therefore, its determination may be applied to verify possible frauds with whey addictions, since it works as a fingerprint. With the description of a new spectrophotometric method for determination of free GMP (ANSM) occurred a simplification of procedures, being faster than others (HPLC method), without loss of accuracy. However, due to variations of glycosilation in kappa-casein between animals, during the lactation period, due to mastitis and yet due to proteolysis on milk, it was necessary to know these variations to interpret correctly the analytical results. It was analyzed 1,703 samples of producer's raw milk and 1,189 samples of processed milk (HTST and UHT). The results showed that normal milk from herd (producer's milk) have only small amounts of free GMP, with A470nm = 0.232±0.088 or 3.89±1.25 mg of sialic acid/L. The upper limit of this distribution was A = 0.496; thus every bigger value may represent a problem, being outside of normal distribution.

Análise histomorfométrica do processo de reparo após o reimplante de dentes de rato mantidos em soro do leite bovino e leite integral

Pós-graduação em Odontologia - FOA

Whey And Soy Protein Supplements Changes Body Composition In Patients With Crohn's Disease Undergoing Azathioprine And Anti-tnf-alpha Therapy.

Crohn´s disease (CD) is a chronic transmural inflammation of the gastrointestinal tract of unknown cause. Malnutrition associated with active CD has been reduced although obesity has increased. Dietary strategies such as those with high-protein have been proposed to reduce body fat. This study compares the effects of two supplements on the nutritional status of CD patients. 68 CD patients were randomized in two groups: whey protein group (WP) and soy protein group (SP). Using bioimpedance analysis, anthropometry and albumin and pre-albumin dosages the nutritional status was measured before starting the intervention and after 8 and 16 weeks. The disease activity was determined by Crohn's Disease Activity Index and serum C-reactive protein dosage and dietary intake by 24h dietary recalls. Forty-one patients concluded the study and both supplements changed body composition similarly. Triceps skin fold thickness (p< 0.001) and body fat percentage (p=0.001) decreased, whereas mid-arm muscle circumference (p=0.004), corrected arm muscle area (p=0.005) and body lean percentage (p=0.001) increased. For Crohn's disease patients undergoing anti TNF-alpha and azatioprine therapies, supplementation with whey and soy proteins changes body composition through reduction of body fat and thus contributes to control inflammation.

Efficacy of sweet solutions for analgesia in infants between 1 and 12 months of age: a systematic review

Objective To compare the efficacy of oral sweet solutions to water or no treatment in infants aged 1-12 months during immunisation. Methods Randomised controlled trials (RCTs) were retrieved through internet searches or manual searches of reference lists. Search terms included newborn, infant, pain, sucrose and alternative names for sweet solutions. Summary estimates with 95% CIs were calculated and included relative risk (RR), risk difference (RD) and number needed to treat to benefit (NNTB) for dichotomous outcomes, and weighted mean differences (WMD) for continuous outcomes. Where pooling of results was not possible, a narrative summary of study results is presented. Results Of the 695 studies identified, 14 RCTs with 1674 injections met the inclusion criteria. Sucrose or glucose, compared to water or no treatment decreased crying during or following immunisation in 13 of the 14 studies. Infants receiving 30% glucose (three trials, 243 infants) had a decreased RR in crying incidence following immunisation (typical RR 0.80, 95% CI 0.69 to 0.93; RD -0.17, 95% CI -0.29 to -0.05; NNTB 6, 95% CI 3 to 20). With sucrose or glucose, there was a 10% WMD reduction in proportion of crying time (95% CI - 18 to - 2) and a 12 s reduction in crying duration (95% CI - 23 to -0.7 s). An optimal dose of sucrose or glucose could not be ascertained due to the varied volumes and concentrations used. Conclusion Infants aged 1-12 months administered sucrose or glucose before immunisation had moderately reduced incidence and duration of crying. Healthcare professionals should consider using sucrose or glucose before and during immunisation.

Analgesic Effects of Sweet-Tasting Solutions for Infants: Current State of Equipoise

OBJECTIVE: The goal was to review published studies of analgesic effects of sweet solutions, to ascertain areas with sufficient evidence of effectiveness and areas of uncertainty. METHODS: Databases searched included Medline, Embase, the Cumulative Index to Nursing and Allied Health Literature database, and PsycINFO, using the terms pain*, infant*, neonat*, newborn*, sucrose, glucose, and alternative sugars. Publications were sorted according to type, year, painful procedure studied, placebo/no-treatment groups, population studied, and country of publication. RESULTS: A total of 298 relevant unique publications involving human infants were identified; 125 (42%) were primary research studies, of which 116 (93%) were randomized controlled trials. Healthy preterm or term newborns were included in 82 studies (65%), and sick or very low birth weight infants were included in 22 (18%). Most studies included single episodes of painful procedures, with only 3 (2%) conducted over long periods. Procedures investigated most frequently were heel lance (49%), venipuncture (14%), and intramuscular injection (14%). Placebo or no-treatment groups were included in 111 studies (89%); in 103 (93%) of those studies, sweet solutions reduced behavioral responses, compared with placebo/no treatment. CONCLUSION: Clinical equipoise relating to analgesic effects of sweet solutions no longer exists for single episodes of procedures for healthy preterm and term newborn infants. Uncertainties include outcomes after prolonged use of sweet solutions, concomitant use of other analgesics, and effectiveness beyond the newborn period. Future research should focus on addressing these knowledge and research gaps. Pediatrics 2010;126:894-902

Optimal fermentation conditions for maximizing the ethanol production by Kluyveromyces fragilis from cheese whey powder

Cheese whey powder (CWP) is an attractive raw material for ethanol production since it is a dried and concentrated form of CW and contains lactose in addition to nitrogen, phosphate and other essential nutrients. In the present work, deproteinized CWP was utilized as fermentation medium for ethanol production by Kluyveromyces fragilis. The individual and combined effects of initial lactose concentration (50-150 kg m(-3)), temperature (25-35 degrees C) and inoculum concentration (1-3 kg m(-3)) were investigated through a 2(3) full-factorial central composite design, and the optimal conditions for maximizing the ethanol production were determined. According to the statistical analysis, in the studied range of values, only the initial lactose concentration had a significant effect on ethanol production, resulting in higher product formation as the initial substrate concentration was increased. Assays with initial lactose concentration varying from 150 to 250 kg m(-3) were thus performed and revealed that the use of 200 kg m(-3) initial lactose concentration, inoculum concentration of 1 kg m(-3) and temperature of 35 degrees C were the best conditions for maximizing the ethanol production from CWP solution. Under these conditions, 80.95 kg m(-3) of ethanol was obtained after 44 h of fermentation. (C) 2011 Elsevier Ltd. All rights reserved.

Comparative study of the biochemical changes and volatile compound formations during the production of novel whey-based kefir beverages and traditional milk kefir

Cheese whey (CW) and deproteinised cheese whey (DCW) were investigated for their suitability as novel substrates for the production of kefir-like beverages. Lactose consumption, ethanol production, as well as organic acids and volatile compounds formation, were determined during CW and DCW fermentation by kefir grains and compared with values obtained during the production of traditional milk kefir. The results showed that kefir grains were able to utilise lactose from CW and DCW and produce similar amounts of ethanol (7.8-8.3 g/l), lactic acid (5.0 g/l) and acetic acid (0.7 g/l) to those obtained during milk fermentation. In addition, the concentration of higher alcohols (2-methyl-1-butanol, 3-methyl-1-butanol, 1-hexanol, 2-methyl-1-propanol, and 1-propanol), ester (ethyl acetate) and aldehyde (acetaldehyde) in cheese whey-based kefir and milk kefir beverages were also produced in similar amounts. Cheese whey and deproteinised cheese whey may therefore serve as substrates for the production of kefir-like beverages similar to milk kefir. (C) 2010 Elsevier Ltd. All rights reserved.

Chemical composition and sensory analysis of cheese whey-based beverages using kefir grains as starter culture

P>The aim of the present work was to evaluate the use of the kefir grains as a starter culture for tradicional milk kefir beverage and for cheese whey-based beverages production. Fermentation was performed by inoculating kefir grains in milk (ML), cheese whey (CW) and deproteinised cheese whey (DCW). Erlenmeyers containing kefir grains and different substrates were statically incubated for 72 h at 25 degrees C. Lactose, ethanol, lactic acid, acetic acid, acetaldehyde, ethyl acetate, isoamyl alcohol, isobutanol, 1-propanol, isopentyl alcohol and 1-hexanol were identified and quantified by high-performance liquid chromatography and GC-FID. The results showed that kefir grains were able to utilise lactose in 60 h from ML and 72 h from CW and DCW and produce similar amounts of ethanol (similar to 12 g L-1), lactic acid (similar to 6 g L-1) and acetic acid (similar to 1.5 g L-1) to those obtained during milk fermentation. Based on the chemical characteristics and acceptance in the sensory analysis, the kefir grains showed potential to be used for developing cheese whey-based beverages.