Effect of the drying method and texture improvers on reconstitution behavior of yogurt powder: physical and microbiological properties

BACKGROUND: One of the most used and effective preservation strategies in foods is drying. However, there are problems with the rheological properties, color, and viability of lactic acid bacteria in the yogurt once reconstituted when applying such conservation strategies. OBJECTIVES: Determine the concentration of the type of texture improver and drying that minimizes the negative effect on the rheological, color, and microbiological properties of a reconstituted yogurt powder. METHODS: Intended to determine the texture improver which increases rheological properties of reconstituted yogurt powder, a mixture type experimental design was applied where three texture improvers were assessed; carboxymethylcellulose (CMC) (mass fraction 0 - 1), pectin (mass fraction 0 - 1), and xanthan gum (mass fraction 0 - 1). The rheological parameters; consistency index (K), flow behavior (n), viscosity at 100s-1 (η), the storage (G') and loss (G'') modules, and the phase shift angle (δ) of each of the reconstitutions were considered as design-dependent variables. Secondly, a central composite design (face-centered) was used for assessing the effectiveness of the drying (convection, spray-drying, and freeze-drying), the concentration of the texture improver (0.0 - 1.0%), and the yogurt powder concentration (8.0 - 15.0%). The above-mentioned rheological parameters, color, and viability of the lactic acid bacteria from each reconstituted yogurt powder were considered as the dependent variables. Optimization sought to match the parameters of reconstituted yogurt powder that approximated the conditions of fresh yogurt. RESULTS: The independent variables in their lineal expression and some interactions between them had statistically significant differences (p < 0.05). At a concentration of 10.59% with 0.03% xanthan gum, the reconstitution of freeze-dried yogurt powder was the optimized condition (p < 0.05) and obtained the rheological, color, and microbiological parameters closest to fresh yogurt. CONCLUSIONS: The drying of the yogurt by freeze-drying mixed with xanthan gum as a texture improver allowed to obtain a reconstituted yogurt with properties close to the fresh product for direct consumption.

Download Full-text

Comparative Survival Rates of Lactic Acid Bacteria Isolated from Blood, Following Spray-drying and Freeze-drying

Food Science and Technology International ◽

10.1177/1082013206062443 ◽

2006 ◽

Vol 12 (1) ◽

pp. 77-84 ◽

Cited By ~ 26

Author(s):

L. M. Zamora ◽

C. Carretero ◽

D. Parés

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Spray Drying ◽

Freeze Drying ◽

Survival Rates ◽

Storage Period ◽

Cellular Damage ◽

Viable Cells ◽

Porcine Blood ◽

Freeze Dried

The effect of two dehydration technologies, spray-drying and freeze-drying, on the viability of 12 lactic acid bacteria (LAB) were compared. All LAB cultures had been previously isolated from porcine blood and were candidates to be used as biopreservatives in order to maintain the quality of porcine blood until further processing to obtain added-value blood derivatives is carried out. The residual viability and the reductions in microbial counts in dried LAB samples at 20 °C and 5 °C during 60-day storage were determined. Cellular damage due to freeze-drying was observed immediately after drying whereas cellular damage due to spray-drying did not become evident until the subsequent phase of storage. For most of the strains, the faster decrease in viability of spray-dried as compared to freeze-dried cultures was compensated by the higher percentage of viable cells obtained after dehydration, leading to comparable survival rates at the end of the storage period. Dehydration resulted in a good alternative to freezing at 80 °C for preservation purposes. Spray-drying has been shown to be as suitable as freeze-drying for preserving LAB strains during a 2-month storage period. Results suggest the possibility of achieving a good formulation system for the LAB strains with a high number of viable cells to be used for the industrial development of bioprotective cultures.

Download Full-text

PENGARUH KONSENTRASI SUKROSA SEBAGAI CRYOPROTECTANT TERHADAP KARAKTERISTIK SIFAT KIMIA YOGHURT SINBIOTIK KERING BEKU

Jurnal Ilmiah Teknosains ◽

10.26877/jitek.v5i2.4533 ◽

2020 ◽

Vol 5 (2) ◽

pp. 81

Author(s):

Yunita Yunita ◽

Agustina Intan Niken Tari ◽

Afriyanti Afriyanti

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Water Content ◽

Freeze Drying ◽

Ash Content ◽

Lactobacillus Bulgaricus ◽

Total Acid ◽

Freeze Dried ◽

Acid Titration ◽

Range Test

ABSTRAKYoghurt sinbiotik merupakan susu fermentasi oleh Bakteri Asam Lakat (BAL) spesies Lactobacillus bulgaricus dan Streptococcus thermophillus, dan Lactobacillus plantarum Dad 13 sebagai probiotik dengan penambahan ubi jalar ungu sebagai prebotik. Yoghurt sinbiotik diproses dengan pengeringan beku. Pada proses pengeringan beku ditambahkan Cryoprotectant untuk mencegah kerusakan membran sel bakteri pada yoghurt. Cryoprotectant berfungsi sebagai pelindung sel bakteri asam laktat selama pembekuan. Tujuan penelitian adalah mengetahui pengaruh konsentrasi Cryoprotectant sukrosa terhadap sifat kimia yoghurt sinbiotik kering beku. Penelitian ini menggunakan Rancangan Acak Lengkap dengan satu variasi yaitu konsentrasi Croprotectant (0%, 2,5%, 5%, 7,5%). Data yang diperoleh dianalisis statistic menggunakan Analysis Of Variance (ANOVA) dengan tingkat signifikan 5% dan jika terdapat perbedaan yang nyata antar perlakuan maka dilanjutkan dengan uji Duncan’s Multiple Range Test (DMRT). Parameter pengamatan yang digunakan untuk menganalisis yoghurt sinbiotik kering beku meliputi kadar air, kadar abu, total asam titrasi, dan pH. Hasil penelitian menunjukkan bahwa konsentrasi Cryoprotectant tidak berpengaruh nyata terhadap kadar air, dan pH yoghurt sinbiotik kering beku, namun berpengaruh nyata terhadap kadar abu dan total asam titrasi. Pengaruh konsentrasi sukrosa sebagai Cryoprotectant diperoleh hasil terbaik pada konsentrasi 5% mempunyai kadar air 5,633%, kadar abu 4,900%, total asam titrasi 8,8167%, dan pH 3.867.ABSTRACTSynbiotic yogurt is fermented milk by Lactic Acid Bacteria (LAB) species Lactobacillus bulgaricus and Streptococcus thermophillus, and Lactobacillus plantarum Dad 13 as probiotics with the addition of purple sweet potatoes as prebotics. Synbiotic yogurt is processed by freeze drying. In the freeze drying process Cryoprotectant is added to prevent damage to bacterial cell membranes in yogurt. Cryoprotectant functions as a protective cell for lactic acid bacteria during freezing. The purpose of this study was to determine the effect of sucrose cryoprotectant concentrations on the chemical properties of freeze dried sinbiotic yogurt. This study uses a Completely Randomized Design with one variation, namely the concentration of Croprotectant (0%, 2.5%, 5%, 7.5%). The data obtained were statistically analyzed using Analysis Of Variance (ANOVA) with a significant level of 5% and if there were significant differences between treatments then continued with the Duncan's Multiple Range Test (DMRT). Observation parameters used to analyze freeze dried synbiotic yogurt include water content, total titration acid, ash content, and pH. The results showed that the concentration of Cryoprotectant had no significant effect on water content, and the pH of freeze dried synbiotic yogurt, but had a significant effect on ash content and total acid titration. Effect of sucrose concentration as Cryoprotectant obtained the best results at a concentration of 5% having a moisture content of 5.633%, ash content of 4.900%, total acid titration of 8.8167%, and pH of 3,867.Keywords: Synbiotic Yogurt, Purple Sweet Potato, Cryoprotectant

Download Full-text

Increased Survival of Lactococcus lactis Strains Subjected to Freeze-Drying after Cultivation in an Acid Medium: Involvement of Membrane Fluidity

Food Technology and Biotechnology ◽

10.17113/ftb.59.04.21.7076 ◽

2021 ◽

Vol 59 (4) ◽

Author(s):

Aurore Bodzen ◽

Audrey Jossier ◽

Sébastien Dupont ◽

Pierre-Yves Mousset ◽

Laurent Beney ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Membrane Fluidity ◽

Lactococcus Lactis ◽

Freeze Drying ◽

Acid Stress ◽

Acidic Condition ◽

Membrane Properties ◽

Freeze Dried ◽

Ph Profiles

Research background. Freeze-drying is the most widely used dehydration process in the food industry for the stabilization of bacteria. Studies have shown the effectiveness of an acid pre-stress in increasing the resistance of lactic acid bacteria strains to freeze-drying. Adaptation of bacteria to an acid stress is based on maintaining the properties of the plasma membrane. Indeed, the fatty acid composition of lactic acid bacteria membrane is often changed after an acid pre-stress. However, few studies have measured membrane fluidity after an acid stress realized during lactic acid bacteria strains cultivation. Experimental approach. In order to use two pH profiles, the strains Lactococcus lactis NCDO 712 and NZ9000 were cultivated in two media, without any pH control. The two pH profiles obtained were representative of initial media composition, media buffering properties, and strains metabolism. Absorbance at 600 nm and pH were measured during bacterial cultivation. Then, the two strains were freeze-dried and their survival rates determined. Membrane fluidity was evaluated by fluorescence anisotropy measurements using a spectrofluorometer. Results and conclusions. Cultivation under a more acidic condition significantly increased both strains survival to freeze-drying (p<0.05, ANOVA). Moreover, in both strains of L. lactis, a more acidic condition during cultivation significantly increased membrane fluidity (p<0.05, ANOVA). Our results revealed that cultivation in such condition, fluidifies the membrane and allows a better survival to freeze-drying for the two strains of L. lactis. A more fluid membrane can facilitate membrane deformation and lateral reorganization of membrane components, critical for the maintenance of cellular integrity during dehydration and rehydration. Novelty and scientific contribution: A better understanding of the involvement of membrane properties, especially of membrane fluidity, in bacterial resistance to dehydration is provided in this study.

Download Full-text

Microencapsulation of Probiotic Strains by Lyophilization Is Efficient in Maintaining the Viability of Microorganisms and Modulation of Fecal Microbiota in Cats

International Journal of Microbiology ◽

10.1155/2020/1293481 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Bruna M. Rodrigues ◽

Paula M. Olivo ◽

Milene P. Osmari ◽

Ricardo S. Vasconcellos ◽

Leonir B. Ribeiro ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Freeze Drying ◽

Animal Feed ◽

Fecal Microbiota ◽

Microbial Viability ◽

Commercial Feed ◽

Freeze Dried ◽

Dry Food ◽

Adult Cats

High extrusion temperatures may compromise the functionality of probiotics in dry food. This study aimed to (i) evaluate the effects of two types of microencapsulation techniques, different encapsulating agents, and 120 days of storage on the viability of a commercial probiotic product and (ii) investigate fecal microbiota populations and fecal characteristics of adult cats fed with diets supplemented with probiotics. Three experimental treatments were evaluated: T1, commercial feed (control); T2, commercial kibbles coated with probiotics; and T3, commercial feed supplemented with freeze-dried probiotics and fructooligosaccharides. Fructooligosaccharides and gum arabic were used as encapsulating agents for freeze drying and spray drying and a pool containing Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus lactis, Bifidobacterium bifidum, Enterococcus faecium, and Saccharomyces cerevisiae as a probiotic. Diets were provided to 18 adult cats for 20 days. Feed samples were evaluated microbiologically, and feces were characterized according to their microbial content, pH, and fecal score. Freeze drying was more effective in maintaining microbial viability. Microcapsules prepared using fructooligosaccharides as encapsulants had the highest bacterial count: 8.74 log CFU/g of lactic acid bacteria and 8.75 log CFU/g of enterococci. Probiotics and synbiotics positively modulated (P<0.05) the fecal microbiota of cats, increasing the lactic acid bacteria counts from 3.65 to 4.87 and 5.07 log CFU/g, respectively. Microbial viability decreased significantly (P<0.05) after storage, demonstrating the need for effective protection mechanisms against extrinsic agents. In conclusion, the supplementation of cat diets with probiotics positively affected the gut microbiota. However, the results reinforce that probiotic microorganisms must be incorporated into the animal feed via effective mechanisms to withstand harsh processing conditions and storage.

Download Full-text

Effect of Cryoprotectant Concentration on Starter Culture Viability Sinbiotic Yogurt with Freeze Dried Sweet Potato Extract Supplementation

International Journal of Advance Tropical Food ◽

10.26877/ijatf.v2i1.6095 ◽

2020 ◽

Vol 2 (1) ◽

Author(s):

Agustina Intan Niken Tari ◽

Catur Budi Handayani ◽

Sri Hartati

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Lactobacillus Plantarum ◽

Sweet Potato ◽

Freeze Drying ◽

Sucrose Concentration ◽

Starter Culture ◽

Protective Material ◽

Freeze Dried ◽

Potato Extract

Synbiotic yogurt with purple sweet potato extract supplementation as prebiotics and Lactobacillus plantarum Dad 13 isolated from buttermilk as probiotics has potential as functional food, but requires low storage temperatures. The freeze drying technique requires cryoprotectant as a protective material for products such as yogurt. The purpose of this study was to determine the effect of sucrose concentration on the level of viability of Lactic Acid Bacteria and Lactobacillus plantarum. This study used a Completely Randomized Design with one factor : concentration of sucrose as cryoprotectant: 0%, 2.5%, 5%, 7.5%, and was carried out in three replications. The results showed that the concentration of sucrose significantly affected the yield of freeze dried synbiotic yogurt, total Lactic Acid Bacteria (LAB) after freeze drying, and total Lactobacillus plantarum before and after freeze drying, but did not significantly total amount of LAB before freeze drying. The best treatment, shown in frozen dried synbiotic yogurt with a sucrose cryoprotectant concentration of 5%. The treatment has the following characteristics: yield, 14.797%, total Lactic Acid Bacteria 1.98x 109 CFU / ml before freeze drying, 9.28x 108 CFU / ml after freeze drying, total Lactobacillus plantarum 8.23 x 108 CFU / ml before freeze drying and 6.81 x 108 CFU / ml after freeze drying.

Download Full-text

Glass transition behavior of carnosine and its impact as a protectant on freeze-dried lactic acid bacteria

Food Biophysics ◽

10.1007/s11483-021-09694-8 ◽

2021 ◽

Author(s):

Shuto Mikajiri ◽

Tomochika Sogabe ◽

Ruodan Cao ◽

Takahiro Kikawada ◽

Toru Suzuki ◽

...

Keyword(s):

Lactic Acid ◽

Glass Transition ◽

Lactic Acid Bacteria ◽

Transition Behavior ◽

Freeze Dried

Download Full-text

Viability of lactic acid bacteria in different components of Ogi with anti diarrhoeagenic E. coli activities

The North African Journal of Food and Nutrition Research - July-December 2021 ◽

10.51745/najfnr.3.6.206-213 ◽

2019 ◽

Vol 3 (6) ◽

pp. 206-213

Author(s):

Roseline Eleojo Kwasi ◽

Iyanuoluwa Gladys Aremu ◽

Qudus Olamide Dosunmu ◽

Funmilola A. Ayeni

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Antimicrobial Properties ◽

Culture Method ◽

Antimicrobial Activities ◽

Drying Methods ◽

Bacterial Strains ◽

E Coli ◽

Log Reduction ◽

Freeze Dried

Background: Ogi constitutes a rich source of lactic acid bacteria (LAB) with associated health benefits to humans through antimicrobial activities. However, the high viability of LAB in Ogi and its supernatant (Omidun) is essential. Aims: This study was carried out to assess the viability of LAB in various forms of modified and natural Ogi and the antimicrobial properties of Omidun against diarrhoeagenic E coli. Methods and Material: The viability of LAB was assessed in fermented Ogi slurry and Omidun for one month and also freeze-dried Ogi with and without added bacterial strains for two months. A further 10 days viability study of modified Omidun, refrigerated Omidun, and normal Ogi was performed. The antimicrobial effects of modified Omidun against five selected strains of diarrhoeagenic E. coli (DEC) were evaluated by the co-culture method. Results: Both drying methods significantly affected carotenoids and phenolic compounds. The Ogi slurry had viable LAB only for 10 days after which, there was a succession of fungi and yeast. Omidun showed 2 log10cfu/ml reduction of LAB count each week and the freeze-dried Ogi showed progressive reduction in viability. Refrigerated Omidun has little viable LAB, while higher viability was seen in modified Omidun (≥2 log cfu/ml) than normal Omidun. Modified Omidun intervention led to 2-4 log reduction in diarrhoeagenic E. coli strains and total inactivation of shigella-toxin producing E. coli H66D strain in co-culture. Conclusions: The consumption of Ogi should be within 10 days of milling using modified Omidun. There are practical potentials of consumption of Omidun in destroying E. coli strains implicated in diarrhea. Keywords: Ogi, Omidun, lactic acid bacteria, diarrhoeagenic Escherichia coli strains, Viability.

Download Full-text

Morphology and Release Kinetics of Protein-Loaded Porous Poly(L-Lactic Acid) Spheres Prepared by Freeze-Drying Technique

ISRN Pharmaceutics ◽

10.5402/2011/490567 ◽

2011 ◽

Vol 2011 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Takashi Sasaki ◽

Kazuki Tanaka ◽

Daisuke Morino ◽

Kensuke Sakurai

Keyword(s):

Lactic Acid ◽

Freeze Drying ◽

Release Kinetics ◽

Particle Surface ◽

Spherical Particles ◽

Freeze Dried ◽

Model Drug ◽

Drug Compound ◽

Kinetics Of ◽

Step Mechanism

Freeze-drying a biodegradable polymer, poly(L-lactic acid) (PLLA), from 1,4-dioxane solutions provided very porous spherical particles of ca. 3 mm in radius with specific surface area of 8–13 m2 g−1. The surface of the particle was found to be less porous compared with its interior. To apply the freeze-dried PLLA (FDPLLA) to drug delivery system, its morphology and drug releasing kinetics were investigated, bovine serum albumin (BSA) being used as a model drug compound. Immersion of FDPLLA into a BSA aqueous solution gave BSA-loaded FDPLLA, where mass fraction of the adsorbed BSA reached up to 79%. Time-dependent release profile of BSA in water suggested a two-step mechanism: (1) very rapid release of BSA deposited on and near the particle surface, which results in an initial burst, and (2) leaching of BSA from the interior of the particle by the diffusion process. It was suggested that the latter process is largely governed by the surface porosity. The porosity of both the interior and surface was found to decrease remarkably as the concentration of the original PLLA/1,4-dioxane solution increases, C0. Thus, C0 is a key parameter that controls the loading and releasing of BSA.

Download Full-text