Goat milk concentrated by nanofiltration: flow decline modeling and characterization

The skimmed goat milk was submitted to the nanofiltration process using a volume reduction factor (VRF) equal to 2. It was verified a rapid decrease of the permeate flux at a low time, with a continuous flux, caused by the reversible resistance, which is characterized by the standard and complete blocking. The combined fouling model was evaluated, including complete pore blocking and cake filtration mechanism, which described the skimmed goat milk nanofiltration behavior. For the VRF equal to 2 was determined the total solids, protein, lactose, ash, mineral fraction content, which increased successfully with the nanofiltration process. The Power Law and Herschel-Buckley models were fitting to describe the flow behavior for retentate, which presented the higher apparent viscosity.Objectius de Desenvolupament Sostenible::12 - Producció i Consum ResponsablesObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraPostprint (published version

Block freeze concentration by centrifugation and vacuum increases the content of lactose-free milk macronutrients

Lactose-free milk is rising in popularity among consumers due to itsclaim to be a better digestible product compared to regular fluid milk. For thatreason, concentrating on this food is a good alternative for increasing its versatil-ity and usability in different dairy industry segments. Block freeze concentration(BFC) is a simple technology used to concentrate liquid foods through ice crystalformation and subsequent removal of water. Thus, this work aimed to test twovariants of the BFC technique on lactose-free milk concentrationPostprint (updated version

Encapsulated Bifidobacterium BB-12 addition in a concentrated lactose-free yogurt: its survival during storage and effects on the product's properties

This work aims to manufacture a new concentrated lactose-free probiotic yogurt. For this purpose, the probiotic Bifidocaterium BB-12 was incorporated in a concentrated lactose-free yogurt, both in its free form and previously encapsulated. Previous cell encapsulation was performed using the spray-drying technique with the following wall materials: lactose-free milk, lactose-free milk and inulin, and lactose-free milk and oligofructose. Thus, three different probiotic powders were obtained and added separately to three fractions of concentrated lactose-free yogurt. The probiotic survival of both powders and yogurts was evaluated during refrigerated storage. Likewise, the viability of starter cultures in yogurt (Lactobacillus bulgaricus and Streptococcus thermophilus) was controlled. In addition, the physicochemical properties of the four yogurts were also measured (color, pH and acidity, and texture properties). All three powders showed good probiotic viability (>8 log CFU g-1) throughout 120 days of storage at 4 ºC. In turn, yogurt formulations (with the addition of powders or free bifidobacteria) presented probiotic viability above 7 log CFU g-1 after storage; as well as the starter cultures (> 8 log UFC g-1). Yogurt with probiotic powder from lactosefree milk showed a more yellowish color; however, these differences would not be detected by the human eye (¿E < 3.00). The yogurt with bifidobacteria free cells showed a greater post-acidification process (pH 4.18 to 4.02 and titratable acidity 1.52 to 1.89). It was not observed differences for firmness values of yogurt with free cells addition and yogurt with lactose-free milk and oligofructose powder addition. A slight significant decrease in the cohesiveness was observed in the yogurt elaborated with bifidobacteria free cells. The gumminess showed fluctuating values between all concentrated lactose-free yogurts. At the end of this study, we conclude that these probiotic powders can be incorporated into innovative lactose-free yogurts.The authors are grateful to the Coordination of Improvement of Higher Education Personnel (CAPES, Brazil) [CAPES-PRINT, Project number 88887.310560/2018-00]; to National Council for Scientific and Technological Development (CNPq, Brazil) by the financial support [CNPq, 405965/2016-8], and Coordination of Improvement of Higher Education Personnel (CAPES, Brazil) by the scholarship [001]Postprint (updated version

Optimization of goat milk vacuum-assisted block freeze concentration using responsesurface methodology and NaCl addition i

Response Surface Methodology was applied to optimize the effects of freezing time, vacuum conditions, and time under vacuum regarding concentrated yield response, resulting from optimal parameters of the milk vacuum-assisted block freeze concentration process. Additionally, it was verified the NaCl influence, using different salt contents (0.5, 1, 1.5, and 2%) addition and freezing time of 1 day, vacuum equal to 10 kPa, and time under vacuum 60 min, in goat milk vacuum-assisted freeze concentration performance.Postprint (updated version

Crioconcentración progresiva de soluciones de sacarosa mediante agitación magnética

En este trabajo se estudia el proceso de crioconcentración progresiva mediante agitación magnética. Los resultados muestran que todas las variables analizadas (concentración inicial, temperatura del refrigerante y velocidad de agitación) afectan significativamente al coeficiente de distribución (k), índice de concentración (IC) y eficiencia (eff).Peer ReviewedPostprint (published version

Vacuum-assisted block freeze concentration studies in cheese whey and its potential in lactose recovery

Block freeze concentration (BFC) is considered an emerging technology which allows the acquiring of high quality organoleptic products, due to the low temperatures employed. In this study we have outlined how the vacuum-assisted BFC of whey was investigated. The effects of vacuum time, vacuum pressure, and the initial solids concentration in whey were studied. The results obtained show that the three variables significantly affect each of the following parameters analysed: solute yield (Y) and concentration index (CI). The best Y results were obtained at a pressure of 10 kPa, 7.5°Bx, and 60 min. For CI parameter, the highest values were given at 10 kPa, 7.5°Bx, and 20 min, respectively. In a second phase, by applying the conditions that provide higher solute yield to three different types of dairy whey, Y values of 70% or higher are reached in a single step, while that the CI of lactose are higher than those of soluble solids. Therefore, it is possible to recover, in a single step, at least 70% of the lactose contained in the initial whey samples. This suggests that vacuum-assisted BFC technology may be an interesting alternative for the recovery of lactose contained in whey.This research received no external funding. The APC was financed by AGRUPS-2022 at Universitat Politècnica de Catalunya (UPC) and SGR-Cat 2021 of Departament de Recerca i Univer- sitats (Generalitat de Catalunya)Objectius de Desenvolupament Sostenible::12 - Producció i Consum ResponsablesPostprint (published version

Lactose-free skim milk and prebiotics as carrier agents of Bifidobacterium BB-12 microencapsulation: physicochemical properties, survival during storage and in vitro gastrointestinal conditions behavior

Bifidobacterium BB-12 was microencapsulated by spray drying using lactose-free milk, lactose-free milk and inulin, and lactose-free milk and oligofructose, resulting in powder 1, 2, and 3, respectively. The highest encapsulation yield (88.01%) and the highest bifidobacteria viability during 120 days of storage were noted for spray-dried powder 2. Spray-dried powders 1 and 3 showing a higher tendency to yellow color. After being submitted to in vitro simulated gastrointestinal conditions, the best probiotic survival rate result was found for spray-dried powder 3 (87.59%). Therefore, spray-dried powders containing prebiotics were the most appropriate combinations for microencapsulation of Bifidobacterium BB-12 and maintenance of cell viability during storage and gastrointestinal system, showing great potential to be used in lactose-free dairy productsPostprint (updated version

Sensorial evaluation of ice-cream elaborated with goat milk

O objetivo deste trabalho foi avaliar sensorial e economicamente formulações de sorvetes obtidos a partir do uso de leite de cabra em pó ou pasteurizado, gordura vegetal hidrogenada e aroma de morango. De vinte e sete formulações inicialmente previstas em um delineamento experimental, utilizando leite de cabra em pó, foram escolhidas as três melhores formulações. Estas três formulações foram avaliadas sensorialmente em três repetições utilizando leite de cabra em pó e três repetições utilizando o leite de cabra pasteurizado. Tanto para o leite em pó quanto para o pasteurizado as formulações escolhidas pelos julgadores foram as elaboradas com as seguintes variáveis: 80 g de gordura vegetal hidrogenada, 0,80 litros de leite de cabra (pó – reconstituído ou pasteurizado) e 0,12 g de aroma de morango. Estas formulações apresentaram Índice de aceitabilidade de 87,1 % para o sorvete elaborado com leite de cabra em pó e 84,3 % para o leite de cabra pasteurizado. Foram realizadas as análises de custo, considerandose apenas os ingredientes da formulação com maior IA, que resultaram num custo de R$3,15 por litro e R$ 2,68 para o sorvete de leite de cabra em pó e para o sorvete de leite de cabra pasteurizado, respectivamente.The objective of this work was to evaluate sensory and economically formulations obtained from of goat powder milk, vegetable fat and strawberry aroma. At least of twenty seven formulations listed in an experimental design, were choiced three best formulations, that they also were elaborated in triplicate to the powder goat milk and pasteurized goat milk. Finally it was choiced the best formulation. The final and the best ice-cream had the following formulation: 80 g of vegetable fat, 0.80 L of goat milk (powder – reconstituted or pasteurized milk) and 0.12 g of strawberry aroma. These formulations shown Acceptability Index (AI) of 87.1 % to ice-cream elaborated with powder milk and 84.3 % to pasteurized milk. Considering just the last and the best AI formulation, it were realized the cost analysis of ice-creams. The price icecream with powder goat milk was equally to R$ 3.15 per liter, while with pasteurized milk was price per liter was equally to 2.68 per liter

Caracterização química e avaliação sensorial de bebida hidroeletrolítica fermentada obtida a partir de permeado de leite tipo C.

Milk permeate was employed to produce a fermented beverage with acceptable sensorial characteristics and chemical composition like a replacer electrolyte, which objective is creating an alternative utilization of this subproduct from cheeses production, obtained by ultrafi ltration process. The ultrafi ltration was performed in a Techniques Industrielles Appliquèes® pilot unity up to 1.2 of volumetric reduction factor, using mineral membrane (50 nm of pore diameter and 0.24 m2 fi ltration area). The permeate fl ux was 27 L.h-1.m-2 at 35,5±0,7°C and transmembrane pressure of 2 bar and permeate fl ow rate of 6 L.h-1. Two treatments were studied: T1 = permeate + sucrose and T2 = permeate + sucrose + milk (3% fat). Each treatment was pasteurized (65°C/30’) and distributed in glass bottles previously sterilized and labelled. Afterwards, each volume was inoculated with Lactobacillus casei subsp. casei, closed and incubated up to pH 4.5. After fermentation, beverages were refrigerated, artifi cially coloured and fl avourized and submitted to sensorial evaluation according to hedonic scale (1 to 9, where: 1 = I disliked it very much and 9 = I liked it very much). Only treatment 2 (T2) obtained an acceptability index higher than 70% (84,4%), moreover presenting high content of calcium, magnesium, potassium, and sodium.Permeado de leite foi usado para elaborar bebida fermentada com características sensoriais aceitáveis e composição química semelhante à de um repositor hidroeletrolítico, com o objetivo de potencializar esse subproduto da fabricação de queijos obtidos por ultrafi ltração. A ultrafi ltração foi realizada em uma unidade piloto da Techniques Industrielles Appliquées® até fator de redução volumétrica de 1,2, utilizando-se membrana mineral com diâmetro médio de poros de 50nm e área fi ltrante útil de 0,24m2. Empregou-se pressão transmembrana, vazão média de permeado e temperatura iguais a 2bar, 6L.h-1 e 35,5±0,7°C, respectivamente, e fl uxo de permeado igual a 27L.h-1.m-2. Foram feitos dois tratamentos: T1 = permeado + sacarose e T2 = permeado + leite tipo C + sacarose. O produto de cada tratamento foi pasteurizado (65°C/30’), acondicionado em garrafas de vidro, previamente esterilizadas e codifi cadas, inoculado com Lactobacillus casei subsp. casei e incubado até pH 4,5. Após a fermentação, as bebidas foram refrigeradas, coloridas e aromatizadas artifi cialmente. Para avaliação sensorial, foi adotado o teste de escala hedônica de 1 a 9 pontos (1 = desgostei muitíssimo e 9 = gostei muitíssimo). Somente a bebida T2 obteve índice de aceitabilidade superior a 70% (84,4%), além de apresentar elevados teores de sais minerais (cálcio, magnésio, potássio e sódio)

THE BEHAVIOR OF THE SKIMMED AND PASTEURIZED BUFFALO´S MILK (Bubalus bubalis) DURING THE ULTRAFILTRATION PROCESS

The aim of this work was to evaluate the skimmed and pasteurized buffalos milk behaviour considering the flow of the permeate (J), the retention percentage (% Rt) and recovery (% Rc) of the components in the retentate during the ultrafiltration process. The average values of the Volumetric Reduction Factor (VRF) and J were 3 and 35 L.h-1.m-2, respectively. The % Rt and % Rc had increased with the VRF growth. The UF of skimmed and pasteurized buffalos milk contributed for a greater % Rt of lipids (100.0%) and proteins (94.8%), including the casein (99.6%) and proteins of the milk whey (82.5%) and a greater % Rc of Ca (99.9%), Mg (81.5%) and P (98.2%).O objetivo deste trabalho foi avaliar o comportamento do leite de búfala desnatado e pasteurizado quanto ao fluxo do permeado (J) e as percentagens de retenção (% Rt) e de recuperação (% Rc) de componentes no retentado durante o processo de ultrafiltração (UF). Os valores médios do fator de redução volumétrico (FRV) e J foram iguais a 3 e 35 L.h-1.m-2, respectivamente. As percentagens de Rt e Rc aumentaram com a elevação do fator de redução volumétrico (FRV). A UF do leite de búfala desnatado e pasteurizado elevou a percentagem de Rt de lipídios (100,0%) e proteínas (94,8%), incluindo a caseína (99,6%) e as proteínas do soro (82,5%), bem como a percentagem de Rc de Ca (99,9%), Mg (81,5%) e P (98,2%)