Abstract The study aimed to encapsulate Lactobacillus rhamnosus GG (LGG) with the selected prebiotic, using co-extrusion technology with a poly-L-lysine (PLL) coating and evaluate probiotic survival in simulated gastrointestinal conditions. Selection of ideal prebiotic was conducted using inulin, fructo-oligosaccharide (FOS) and isomalto-oligosaccharide (IMO) and its optimal concentration to be incorporated in microencapsulation was determined. Microcapsules without coating (S1: no prebiotic and S3: with prebiotic) and with coating (S2: no prebiotic and S4: with prebiotic) produced were evaluated based on its physical properties and survival in simulated gastrointestinal environment. The IMO with a concentration of 3.0% (w/v) was selected due to its best effect in promoting growth of LGG after 24 h (8.63±0.07 log CFU/mL). The morphology analysis revealed that all microcapsules produced were spherical with a diameter ranging from 491.3 to 541.7 µm and microencapsulation efficiency ranged from 84.16 ±5.30% to 90.56±3.33%. The incorporation of IMO and coating with PLL improved the survival of LGG by 3% up to 52% after 2 h of incubation in simulated gastric digestion. Among all formulations, PLL coated microcapsules added with IMO was the most effective in protecting LGG during the first hour of simulated gastric digestion (6.52 log CFU/mL) with cell viability greater than the minimum recommended level of 106 CFU/mL.

RESUMO Lactobacillus acidophilus NCFM (L-NCFM) foi microencapsulado pela técnica de coextrusão com manitol. A otimização do material de revestimento, goma de alfarroba (0% a 2%, p / v) e prebiótico, manitol (0% a 5%, p / v) foi testada no tamanho do grânulo e eficiência de microencapsulação. Células L-NCFM microencapsuladas em três formas diferentes foram testadas em suco gástrico simulado (pH 2,0) e suco intestinal simulado (pH 7,5) e teste de armazenamento a 4 °C e 25 °C por 4 semanas. 0,5% (p / v) de goma de alfarroba e 3% (p / v) de manitol são as concentrações óptimas para produzir um tamanho de pérola de 570 µm, eficiência de microencapsulação de 96,81% e contagem de células 8,92 log CFU / mL. A microencapsulação de L-NCFM com manitol protege melhor as células em ambiente ácido. A viabilidade de L-NCFM encapsulado com manitol a 4 °C durante o período de armazenamento por 30 dias variou de 8,62 log ufc / mL a 6,80 log ufc / mL, atendendo ao mínimo necessário para probiótico (106 UFC / mL).

ABSTRACT Lactobacillus acidophilus NCFM (L-NCFM) was microencapsulated via co-extrusion technique with mannitol. Optimization of coating material, locust bean gum (0% to 2%, w/v) and prebiotic, mannitol (0% to 5%, w/v) was tested on bead size and microencapsulation efficiency. L-NCFM cells microencapsulated in three different forms were tested in simulated gastric juice (pH 2.0) and simulated intestinal juice (pH 7.5) and storage test at 4 °C and 25 °C for 4 weeks. 0.5% (w/v) locust bean gum and 3% (w/v) of mannitol are the optimal concentrations to produce bead size of 570 µm, microencapsulation efficiency of 96.81% and cell count 8.92 log CFU/mL. Microencapsulation of L-NCFM with mannitol protect cells better in acidic environment. The viability of encapsulated L-NCFM with mannitol at 4 °C throughout the storage period for 30 days ranged from 8.62 log cfu/mL to 6.80 log cfu/mL, which met the minimum required for probiotic (106CFU/mL).

RESUMO Ervas e especiarias, tendo efeito antimicrobiano, podem ser incorporadas em filmes comestíveis, para prolongar a vida de prateleira do produto e reduzir o risco de crescimento microbiano nos alimentos. Este estudo tem como objetivo desenvolver um filme de quitosana incorporado com Garcinia atroviridis, também conhecido como “asam gelugur”, “asam gelugo”, ou “asam keping”. O filme com diferentes concentrações de Garcinia atroviridis (1-5% v/v) com quitosana (1.5% w/v) foi investigado por suas propriedades físicas e mecânicas. Com o aumento do extrato de Garcinia atroviridis incorporado, a solubilidade em água dos filmes aumenta (de 21.17 para 53.61%). O aumento do Garcinia atroviridis incorporado ao filme de quitosana também aumenta a diferença total de cor. Filme com maior concentração de extrato de Garcinia atroviridis produziu filme mais espesso comparado ao filme sem extrato (de 0.048 a 0.143 mm). O filme com 5% (v/v) de Garcinia atroviridis apresentou baixa resistência à tração (3.28 MPa) e alongamento (13.90%). O módulo de Young foi diminuído em valor (de 0.72 a 0.24 MPa) à medida que a maior concentração de extrato de Garcinia atroviridis foi adicionada. O extrato de Garcinia atroviridis (5% v/v) nos filmes de quitosana demonstrou maior atividade inibitória contra bactérias (Pseudomonas aeruginosa, Bacillus subtilis e Staphylococcus aureus). Com a película comestível de 5% (v/v) de Garcinia atroviridis aplicada, a cavala indiana apresentou uma vida útil mais longa (3,5 dias) em comparação com o controle (2,5 dias).

ABSTRACT Herbs and spices, having antimicrobial effect, can be incorporated into edible films, to extend product shelf life and the reduce the risk of microbial growth on food. The aim of this study is to develop chitosan film incorporated with Garcinia atroviridis, also known as ‘asam gelugur’, ‘asam gelugo’, or ‘asam keping’. The film with different concentrations of Garcinia atroviridis (1 to 5% v/v) with chitosan (1.5% w/v) were investigated for its physical, mechanical and antibacterial properties. With the increase of Garcinia atroviridis extract incorporated, water solubility of the films increases (from 21.17 to 53.61%). Increase of Garcinia atroviridis incorporated into chitosan film also increase the total color difference. Film with higher concentration of Garcinia atroviridis extract produced thicker film compared to the film without extract (from 0.048 to 0.143 mm). The film with 5% (v/v) Garcinia atroviridis possessed low tensile strength (3.28 MPa) and elongation at break (13.90%). Young’s modulus was decreased in value (from 0.72 to 0.24 MPa) as the higher concentration of Garcinia atroviridis extract was added. High Garcinia atroviridis extract (5% v/v) in the chitosan films demonstrated greater inhibitory activity against the bacteria strains (Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus). With the edible film of 5% (v/v) Garcinia atroviridis applied, the Indian mackerel was found to have a longer shelf life (3.5 days) as compared to the control (2.5 days).