Cream Fermentation Research Articles

Physicochemical changes during cream fermentation and quality characteristics of lactic butter produced using cultured creams with different fermentation levels

Physicochemical changes during cream fermentation and the effects of cream fermentation on lactic butter (LB) characteristics were investigated. The pH decreased and acidity increased with lactic acid bacteria (LAB) growth during cream fermentation. The fat globule size of cultured cream (CC) also increased as cream fermentation progressed, leading to an increase in rheological parameters (ηa,50, K, and σoc) and a decrease in churning time. Cream fermentation had a significant effect on the quality characteristics, such as acidity, acid value, and hardness of LB. The acidity of LB was increased by LAB, which can contribute to the sour taste of LB. In addition, spreadability of LB was improved by cream fermentation. These results suggest that LB characteristics can be effectively controlled by adjusting the cream fermentation levels.

Sheep's Butter and Correspondent Buttermilk Produced with Sweet Cream and Cream Fermented by Aromatic Starter, Kefir and Probiotic Culture.

Small ruminant dairy products are common in some Mediterranean countries, in the Middle East and Africa, and can play a particular role in the development of rural areas. Butter has been the object of few research studies aimed at evaluating its potential as a vehicle for probiotic microorganisms. Moreover, the recovery of fermented buttermilk with functional properties can be considered an excellent opportunity to value this dairy byproduct. Therefore, the purpose of the present work was to develop different sheep butters and respective buttermilks after cream fermentation by: (1) a mesophilic aromatic starter (A); (2) a kefir culture (K); and (3) a mixture of probiotic bacteria (P). The butters and buttermilk produced with fermented cream were compared with non-fermented sweet cream (S) butter or buttermilk, respectively, regarding their physicochemical, microbiological and sensory characteristics. The adjusted production (%, w/v) obtained for butter were: S (44.48%), A (36.82%), K (41.23%) and P (43.36%). S, A and K butters had higher solids, fat and ashes contents than P butter. The probiotic butter had a total fat of ca. 75% (w/w), below the legal limits, while all others had fat levels above 81.5%. In all samples, the pH decreased and the acidity increased over 90 days of refrigerated storage. These variations were more evident in the P butter, which agrees with the highest lactic acid bacteria counts found in this sample. Differences in color between samples and due to storage time were also observed. In general, the butter samples tended to become darker and yellower after the 60th day of storage. Texture analysis showed comparable results between samples and greater hardness was observed for the P butter, most probably due to its higher relative saturated fatty acids content (66.46% compared to 62−64% in S, A and K butters). Regarding rheological properties, all butters showed pseudoplastic behavior, but butter P had the lowest consistency index (249 kPa.sn−1). The probiotic butter and the corresponding buttermilk had viable cell counts greater than 7 Log CFU/g, indicating their suitability as probiotic carriers. All products were well accepted by consumers and small, but non-significant, differences (p > 0.05) were observed in relation to the sensory parameters evaluated. In general, it can be concluded that the use of adequate starter cultures can allow the production of innovative and potentially healthier products, alongside the valorization of dairy byproducts, improving the income of small-scale producers.

Биотехнологические аспекты подготовки ферментированных сливок для обогащения творожного продукта пробиотическими культурами

Introduction. Contemporary food industry strives to increase the production volume of high-quality and biologically complete protein products. The Foodnet market also raised the demand for functional foods in Russia. The research objective was to develop a new functional curd product fortified with probiotic microflora.
 Study objects and methods. The study featured cow’s milk, skimmed milk, cream, whey protein concentrate Milkiland-WPC 80, pollen, glutamine, starter cultures DVS Danisco Probat 576 and Howaru Bifido ARO-1, buckwheat flour, and oat flour. The experiment included physicochemical, sensory, biochemical, and microbiological methods.
 Results and discussion. The milk-protein base of the curd product was produced in a GEA Westfalia KDB 30 curd separator. The research involved 15 and 20% cream with two different starter cultures. In case of 15% cream, Probat 576 Howaru Bifido appeared to be 1.66 times more active than ARO-1 Howaru Bifido, in case of 20% cream the result was even higher – 1.73 times. Probat 576 also demonstrated a better active acidity, i.e. 5.5 after three hours, which was two hours faster than ARO-1. Mathematical modeling revealed the positive effect of buckwheat and oat flour on the cream fermentation process. Oat flour (5%) was the optimal prebiotic, while buckwheat flour added its color to the final product, thus spoiling its market quality.
 Conclusion. The new biotechnology for a curd product fortified with probiotic cultures can expand the range of functional products for sports diet.

Simulation of synbiotic ice cream fermentation process

Expanding the range of products of therapeutic and prophylactic orientation is a priority direction of the state policy in the field of healthy nutrition. Products enriched with functional components improve the general state of the body, have high organoleptic characteristics in combination with increased biological value. The production of synbiotic ice cream is one of the promising trends in the dairy industry. Due to its unique composition and technological peculiarities, the ice cream retains the desired organoleptic and functional properties. Pro- and prebiotic components in it are conserved by freezing, and activated only when they enter the organism. It has been established experimentally, that high concentrations of monosaccharides have an inhibitory effect on the development of probiotic cultures, therefore, the purpose of the research is to simulate the fermentation process of the ice cream enriched with prebiotic components, in order to determine optimal characteristics and establish rational syrup concentrations. Lactic bacteria of Lactobacillus acidophilus species that remain active in a wide temperature range and suppressing pathogenic microflora, as well as berry syrup with a high concentration of vitamins and minerals have been used as components that ensure the functionality of the product. Phased addition of syrup has been recommended for the ex- periment. As a result of the research, a model recipe for synbiotic ice cream has been developed, the quantitative regularities of the influence of various concentrations of fructose syrup on the process of fermentation of compound have been determined, organoleptic characteristics of soft-serve ice cream have been investigated, a power-law model of the dependence of the duration of fermentation on the mass fraction of fructose syrup has been obtained. It has been found that a decrease in the initial concentration makes it possible to shorten the technological cycle and regulate the acidity index.

Adding value and innovation in dairy SMEs: From butter to probiotic butter and buttermilk

Enhancing the nutritional/economical value of small/medium size dairy enterprises products is important for their survival in a competitive market. Probiotic fermented dairy products is a trend driven by consumer's acceptance of such products. This study intends the production of probiotic butter with the side possibility of buttermilk valorization by confirming the minimum microbial counts required to claim the probiotic properties of the novel products. Pasteurized milk inoculated with commercial probiotic culture was added to cream, alone or combined with aromatic starters and fermented during 34 hr. Probiotic microorganisms counts evaluated throughout cream fermentation present a final value of around 8 Log CFU/ml. Butter presented values higher than 6 Log CFU/g, within the reference values required to be considered as a probiotic, being softer and with higher humidity than conventional butter. Fermented buttermilk, having the potential commercialization as a probiotic dairy beverage, was also obtained representing a significant contribution to the circular economy. Practical applications The use of probiotic fermented dairy products is a trend in the food industry driven by consumer's acceptance and awareness of their health benefits. In this context the production of probiotic butter, with the side possibility of buttermilk valorization, can improve the nutritional and economical value of the products of small/medium size dairy companies contributing for their survival in today's competitive market. This work describes the production process optimization which can also contribute for the valorization of buttermilk through the production of a probiotic drink.

The ability of spore formers to degrade milk proteins, fat, phospholipids, common stabilizers, and exopolysaccharides

Spore formers are common spoilage-causing microorganisms in dairy products; however, their modes of spoilage (proteolysis, lipolysis, etc.) have not been described in detail for cultured dairy products such as sour cream and yogurt. The objective of the present study was to test the ability of spore-forming strains isolated from dairy environments for their spoilage-causing activities at typical sour cream (24°C) and yogurt (42°C) fermentation temperatures. A total of 25 spore-forming strains were isolated from different sources, including raw milk, pasteurizer balance tank, biofilms formed on heat exchangers, and milk powder. These strains were tested for proteolytic and lipolytic activities and for their ability to degrade phospholipids, common stabilizers (starch, gelatin, xanthan gum, pectin), and exopolysaccharides (EPS) at sour cream and yogurt fermentation temperatures. A higher percentage of positive strains was observed for selected activities at yogurt fermentation temperature compared with sour cream fermentation temperature. Identified proteolytic spore-forming strains, based on a skim milk agar method, were subsequently quantified for their level of proteolysis using non-casein nitrogen (NCN) content and sodium dodecyl sulfate-PAGE (SDS-PAGE). The proteolytic strains that showed the highest levels of proteolysis (highest percentages of NCN content) at 24°C were Bacillus mojavensis BC, Bacillus cereus DBC, Bacillus subtilis DBC, B. mojavensis DBC1, and Paenibacillus polymyxa DBC1. At 42°C the strains with the highest levels of proteolysis (highest percentages of NCN content) were B. subtilis DBC, B. mojavensis BC, B. mojavensis DBC1, B. cereus DBC, and Bacillus licheniformis DBC6. Results of SDS-PAGE demonstrated that proteolytic strains had primarily hydrolyzed β- and κ-CN. A viscometric method was used to evaluate the susceptibility of exopolysaccharides (EPS) to degradation by selected spore formers. This method helped to determine that EPS produced by commercial yogurt and sour cream cultures is susceptible to degradation by spore formers present in dairy environments.

Research into probiotic properties of cultured butter during storing

The purpose of experimental research was to determine the number of viable cells L. acidophilus of the strain La-5 and Flora Danica when storing cultured butter. For this purpose, we employed different temperature modes of the fermentation of cream, as well as various technologies. The original concentration of cultures in cream is 1•106 cfu/cm3; with a combination of cultures – the ratio of 1:1 at original concentration in cream of 1•106 and 1•106 cfu/cm3, respectively). We prepared 4 groups of butter: – group I (samples BW (Butter Winter)1, BW2, BW3 and BS (Butter Summer)1, BS2, BS3 at souring the cream by FD, FD + La-5, La-5, respectively, in winter and summer). Cream fermentation was conducted at temperature (30±1) oC; – group II (BW4, BW5, BW6, BS5, BS6, BS7 at souring by FD, FD+La-5; La-5) – fermentation (37±1) oC; – group III (З7, З8, З9 at souring by FD, FD+La-5, La-5, respectively) – (8±1) oC→(20±1) oC→(12±1) oC – winter stepwise cultured butter production mode similar to the Alnarp mode. (BS7, BS8, BS9) – (20±1) oC→(6±1) oC→(10±1) oC – summer stepwise mode similar to the Danish one; – group IV (BW10, BW11, BW12, BS10, BS11, BS12 at souring by FD, FD+La-5, La-5, respectively) – introduction of souring cultures to a butter grain. The original concentration of cells at inoculation – 1•108 cfu/cm3. The largest number of viable cells of La-5 was registered for the sample in which we used FD+La-5 and the fermentation of cream at temperature (30±1) oC. Duration of storing the cultured butter with the probiotic properties is 35 days at temperature 0…–5 oС

STUDY OF KEEPING PROBIOTIC PROPERTIES OF SOUR-CREAM BUTTER AT STORAGE

The aim of the work was the study of keeping probiotic properties of sour-milk butter with inclusion of Lactobacillus acidophilus La-5 (La-5) monoculture. Flora Danica mesophile culture independently (FD); in combination with La-5 and La-5 independently were used for fermenting cream. The output consistence of culture in cream was 1×106 CFU/cm3. In autumn-winter and spring-summer period of the year four butter groups were prepared, they differed by temperature of cream fermentation: I group – (30±1) ºС; II – (37±1) ºС; III – stage regimes of combination of fermentation and physical maturing; IV group – introduction of cultures into oil kernel; the output concentration – 1·108 CFU/cm3. As to the features of summer and winter periods, in summer one cream fermentation is more active that is indicated by more number of cells of both microbial cultures. The best parameters of viable cells keeping were typical to the samples at FD+La-5 use and temperature of cream fermentation (30±1) ºС. Storage life of sour-cream butter with probiotic properties is 35 days at temperature 0…-5 ºС.

ДОСЛІДЖЕННЯ ПРОЦЕСІВ ФЕРМЕНТАЦІЇ ТА ФІЗИЧНОГО ВИЗРІВАННЯ ВЕРШКІВ У ВЕСНЯНО-ЛІТНІЙ ПЕРІОД РОКУ ПРИ ВИРОБНИЦТВІ МАСЛА З ПРОБІОТИЧНИМИ ВЛАСТИВОСТЯМИ

Метою досліджень було встановити та обґрунтувати оптимальні параметри ферментації та фізичного визрівання вершків при виробництві кисловершкового масла у весняно-літній період року за поєднання класичних для масла змішаних мезофільних культур Flora Danica (FD) – Lactococcus lactis ssp. cremoris, Lactococcus lactis ssp. lactis, Leuconostoc mesenteroides ssp. cremoris, Lactococcus lactis ssp. diacetylactis із термофільною монокультуроюLactobacillus acidophilus пробіотичного штаму La-5 (La-5). Було виготовлено чотири групи кисловершкового масла. У заквашених вершках контролювали активність кислотоутворення за зміною титрованої і активної кислотності та кислотність плазми.
 Встановлено можливість поєднання класичних змішаних мезофільних культур FD з термофільною монокультурою L. acidophilus пробіотичного штаму La-5 за ферментації вершків у технології кисловершкового масла з пробіотичними властивостями. Експериментально встановлено дозу інокуляції і раціональне співвідношення між FD і La-5 у складі заквашувальної композиції безпосереднього внесення – 1 : 1 при вихідній концентрації кожної культури у вершках 1·106 КУО/см3 для виробництва кисловершкового масла з пробіотичними властивостями. Встановлено параметри процесу ферментації та фізичного визрівання вершків за поєднання заквашувальних культур FDта La-5 у весняно-літній період року: температура ферментації (30 ± 1) ºС, тривалість 4 год.; температура фізичного визрівання (5 ± 1) ºС, тривалість 6 год.

Effect of cream fermentation on microbiological, physicochemical and rheological properties of L. helveticus-butter

The primary objective of this study was to evaluate the physicochemical and rheological properties of butter produced by Lactobacillus helveticus fermented cream. The incorporation of putative probiotic – the L. helveticus, to ferment cream prior to butter production was anticipated to alter the nutritional composition of butter. Changes in crude macronutrients and the resultant modification relating to textural properties of butter induced upon metabolic activities of L. helveticus in cream were focused in this research. Fermented butter (LH-butter) was produced by churning the cream that was fermented by lactobacilli at 37°C for 24h. Physicochemical analysis, proximate analysis and rheology properties of LH-butter were compared with butter produced using unfermented cream (control). LH-butter showed a significantly (P<0.05) higher fat content and acid value; lower moisture and ash; and was softer than the control. Cream fermentation modified nutritional and textural properties of butter in which LH-butter contained higher health beneficial unsaturated fatty acids than the control and thus rendered the product softer. Its enrichment with probiotics could thus further enhance its functional property.

РОЗРОБКА РЕЖИМУ ФЕРМЕНТАЦІЇ БІЛКОВОЇ МАСИ У ТЕХНОЛОГІЇ БІЛКОВИХ ПАСТ ДЛЯ ДИТЯЧОГО ХАРЧУВАННЯ

Basing on the analysis of the market for baby food products in Ukraine, the paper shows the prospects of the development of innovative technologies for food protein pastes used for the nutrition of children of 8 months and upwards with high probiotic, antagonistic and hypoallergenic properties, high bioavailability and biological efficiency, and extended storage period; the prospects of three ways of implementation of the thermostat production mode of protein pastes for baby food are also defined here. The protein cream fermentation mode is grounded here in which the protein cream is enriched with lactulose, a complex of vitamins FT 041081EU and / or a complex of minerals FT 042836EU in the technology of protein pastes for baby food products with the usage of sour compounds based on bifidobacteria and lactobacilli bacterial concentrates obtained by freezing and freeze-drying with fermentation temperature of (37 ± 1) °C and duration of 5.5 hours. Being singled out are also prospects of using protein pastes for baby food products which have bacterial concentrates of high probiotic and proteolytic properties and are based on mixed cultures Lac. lactis ssp. (F DVS C-301 or F DVS C-303 ) and monocultures Bifidobacterium animalis Bb-12 (F DVS Bb-12) obtained by freezing. The paper shows the stimulating effect of complex vitamins and minerals on the growth of bifidobacteria, lactobacilli and mesophilic lactic-acid lactococci in the protein cream; defines the synergistic impact of the stimulating effect of the vitamins and minerals complexes joint use on bifidobacteria and lactobacilli growth. The organoleptical, physical, chemical and microbiological parameters of fermented protein cream are also defined and its advantages over sour-milk cheese for baby food produced by dairy milk processing plants are singled out.

ОБГРУНТУВАННЯ ПАРАМЕ-ТРІВ ФЕРМЕНТАЦІЇ МОЛОЧНО-РОСЛИННИХ ВЕРШКІВ У БІОТЕХНОЛОГІЇ БІЛКОВИХ ПАСТ ДЛЯ ДИТЯЧОГО ХАРЧУВАННЯ

In this work the analysis of Ukrainian baby food market was carried out; there were reflected the prospects of development of protein paste technologies for baby food with the use of bacterial concentrates of lacto- and bifidobacteria of direct insertion with increased probiotic and proteolytic properties; there were shown the prospects of protein paste production by separation method with the use of thermal acid or thermal calcium method of protein separation from skim milk; the parameters of milk-vegetative cream fermentation enriched with fructose as a bifidogenic factor, starter composition made of bacterial concentrates of direct insertion of milk adapted bifidobacterium animalis bb-12 (fd dvs bb-12) and bacterial concentrates of mesophilic lactococcus (lac. lactis ssp. lactis, lac. lactis ssp. cremoris, lac. lactis ssp. diacetilactis і leu. mesenteroides), were proved; recommendations concerning the fermentation regimen of enriched milk-vegetative cream: temperature (37±1) °С, duration 11,5 – 12,0 hours were presented.

Production of flavour-active methionol from methionine metabolism by yeasts in coconut cream

Yeasts Candida kefyr NCYC143, Candida utilis CUM, Kluyveromyces lactis KL71, Saccharomyces bayanus SB1, Saccharomyces cerevisiae EC1118, Saccharomyces chevalieri CCICC1028, Candida famata (previously Torulopsis candida) CCICC1041 and Williopsis saturnus var. saturnus CBS254 were screened for their ability to produce flavour-active methionol (3-methylthio-1-propanol) in coconut cream supplemented with l-methionine. The yeasts varied with their ability to produce methionol from methionine with Saccharomyces cerevisiae EC1118 producing the most, followed by Kluyveromyces lactis KL71. Little methionol was produced by the other yeasts. Methionol production by Kluyveromyces lactis KL71 was subjected to further studies under different conditions of initial pH (4.0–6.3), temperature (20–33 °C), l-methionine concentration (0.05–0.25%) and yeast extract concentration (0-0.50%); optimal conditions were established at pH 5.0, 33.0 °C, 0.15% l-methionine and 0.05% yeast extract. CharmAnalysis™ using SPME-GC-MS was conducted on the coconut cream ferment; methional (3-methylthio-1-propanal), methionol and 2-phenylethyl acetate were found to be the most potent aroma-active compounds. The product of coconut cream fermentation by Kluyveromyces lactis KL71 may be considered as a novel, plant-based, natural and complex flavoring bioingredient in food applications.

Cream fermentation by a mixed culture of lactococci entrapped in two-layer calcium alginate gel beads

This investigation was directed towards the development of a process which produces a fermented cream of greatly reduced cell number.Lactococcus lactis subsp.Lactis andLactococcus lactis subsp.lactis biovardiacetylactis were entrapped separately in normal or two-layer Ca-alginate gel beads. Pasteurized cream (31% fat content) was inoculated with free-cells and with normal or two-layer beads. When 8% of the total volume was occupied by the gel, there was 300–800 times more inoculum in this system and the fermentation time was considerably reduced (5h against 18h). When pH 5.0 was reached, the residual free-cell count was 150 and 1800 times less than for a classical inoculation method with free-cells for normal and two-layer beads respectively. This result was reproducible for several consecutive runs. Also, the problems linked to storage acidification (souring, wheying-off) appeared later and living lactic acid bacteria were maintained in the product.

Cream fermentation by immobilized lactic acid bacteria

Mesophilic lactic acid bacteria were immobilized in calcium alginate gel and added to pasteurized 15% fat cream at a 1.6x109 bacteria per ml inoculation level. A pH of 5.5 was obtained in only two hours while it took 4 hours under classical conditions. Once the immobilized cells were removed, the cream contained 6.1x106 lactic bacteria per ml which was almost 400 times less than the bacterial population obtained at pH 5.5 under a classical fermentation. The fermented cream obtained from immobilized cells showed much less overacidification under subsequent refrigeration.