Fermentation process for production of apple-based kefir vinegar: microbiological, chemical and sensory analysis

Abstract The aim of this study was to develop a kefir apple-based vinegar and evaluate this fermentation process using new methodology with Biospeckle Laser. Brazilian kefir grains were inoculated in apple must for vinegar production. In this study, the microbial community present in kefir, and correspondent vinegar, was investigated using Matrix Assisted Laser Desorption/Ionization - Time of Flight Mass Spectrometry (MALDI-TOF MS) technique. Saccharomyces cerevisiae, Lactobacillus paracasei, Lactobacillus plantarum, Acetobacter pasteurianus and Acetobacter syzygii were the microbial species identified. S. cerevisiae, L. plantarum, A. pasteurianus and A. syzygii were found in smaller quantities at the beginning of the alcoholic fermentation, but were found throughout the alcoholic and acetic fermentation. Kefir grains were able to utilize apple must as substrate to produce ethanol, and acetic acid. Acetate, volatile alcohols and aldehydes in the vinegar-based kefir were also produced. The yield of acetic acid in the kefir vinegars was ∼79%. The acetic acid concentration was ∼41 g L-1, reaching the required standard for the Brazilian legislation accepts it as vinegar (4.0% acetic acid). Kefir vinegar showed good acceptance in the sensory analysis. The technology proposed here is novel by the application of immobilized-cell biomass (kefir grains) providing a mixed inocula and eliminating the use of centrifuge at the end of the fermentative process. This step will save energy demand and investment. This is the first study to produce apple vinegar using kefir grains.

Effects of the protective, curative, and eradicative applications of chitosan against Penicillium expansum in apples

Abstract Apple is one of the most important temperate fruit to Brazil economy, and the use of synthetic chemicals has been the main method for reducing postharvest diseases, such as the blue mold, caused by Penicillium expansum. This work intends to evaluate the practical utilization of chitosan for blue mold control. For this purpose, fruits were treated in a preventive and curative way, immersing the fruits in chitosan solution (5 or 10 mg mL-1), or adding a single drop of this solution (10 mg mL-1) directly into the injuries. The eradicative effect of the polysaccharide was also evaluated in vitro and in vivo. Chitosan did not show a curative effect against the blue mold, and its eradicative effect was only evidenced on the higher concentration (10 mg mL-1). On the other hand, preventively, without the addition of adjuvants, chitosan reduced blue mold incidence in fruits by 24% and 93%, through the immersion or the single drop methods, respectively. Thus, it was found that, for long scale utilization, some improvements in the physico-chemical properties of the chitosan are needed, since it was only capable to prevent the infection by P. expansum when directly added on the fruit injury.

Diagnostic and environmental study of Aspergillus terreus isolated from various varieties of apples fruits

Objectives: This study includes the fungi isolated from apple fruits and diagnosis study with ecological factors for Aspergillus terreus

Methods: The samples were collected from apple varieties which included red importer apples, red local apples, golden yellow importer apples, green importer apples. The collected apples had some obvious lesion or spoilage and isolated number of fungi that differences in appearance percent and used two primers SEQ ID NO and ITS for A. terreus diagnosis by using PCR technique; in addition the study includes using three factors effective on fungal growth with temperature 15, 20, 25, 30 and 35[degree]C with pH 4, 6, 8, 10 and 12 and the third factor culture medium PDA, SDA, CZA and MEA

Results: Results revealed the presence of nine types of fungi which includes P. expansum, Rhizopus solonifer, Alternaria spp, A. flavus, A. niger, A. terreus, P. digitatum, P. italicum and yeast isolated from various apple fruits. Number of isolates P. expansum more than other fungi while less number was found in Rhizopus stolonifer. The A. terreus identified by amplicon size of that appear 100 bp for six isolates and it appears that four isolates carrying this gene has size of 600 base pairs. This study showed significant differences [p < 0.05] in effect of five temperatures 15, 20, 25, 30 and 35[degree]C in the growth of fungus A. terreus and pH levels on growth on three isolates of genus the types of culture media [PDA, SDA, CDA, MEA] significant at p < 0.05 affected the growth of A. terreus and it had different morphological characteristics

Conclusion: Number of fungi was found in apple and identified A. terreus by PCR method and studied different ecology factors on growth fungus. The best degree for the growth of isolates in the sixth day was 30[degree]C. Maximum level of growth of the A. terreus was at pH 6 for all isolates in the sixth day and the growth rate for the same day on SDA reached 7.13 cm which was considered the best media for growth

Propiedades saludables y calidad sensorial de snack de manzanas destinadas a alimentacion escolar

Se desarrolló un snack de manzana con el fin de introducir el consumo de alimentos derivados de frutas para disminuir la obesidad en escolares de Santiago de Chile. Se deshidrataron rodelas de manzanas, con la piel incluida, de variedad Fuji a 60ºC por 4 horas obteniendo un producto con 4,6 g/100 g de humedad y actividad de agua (Aw) de 0,56 . El snack de manzanas presentó 24,8 ± 0,3 g/100 g b.s. de fibra dietética y 550,16 ± 5,89 mgGAE/100 g b.s. de polifenoles lo que lo convierte en un alimento saludable, presenta además alta capacidad antioxidante medida por FRAP, con 0,59 mmolFe/100g . El análisis sensorial realizado en escolares de 8 y 12 años indica que el producto presenta alta aceptabilidad, es un producto crocante, de textura crujiente, con sabor agridulce, por lo que se constituye en una alternativa para colaciones escolares.

An apple snack has been developed with the purpose of introducing foods derived from fruit to reduce obesity in school children of Santiago, Chile. Apple slices of the ‘Fuji’ variety were dehydrated, with skin included, at 60°C for 4 h obtaining a product with 4.6 g/100 g of humidity and water activity (Aw) of 0.56. The apple snack presented 24.8 ± 0.3 g/100 g b.s. of dietary fiber and 550.16 ± 5.89 mgGAE/100 g b.s of polyphenols which converts into a healthy food, it also presents high antioxidant capacity measured by FRAP, with 0.59 mmolFe/100g. The sensory analysis done in school children between the ages of 8 and 12 years old indicates that the product presents high acceptability, is a crispy product, of a crunchy texture, with bittersweet flavor, so it is an alternative for school snacks.

Uso de análise de imagens no acompanhamento de contaminação por fungos em frutos minimamente processados / Use of image analysis in monitoring fungal contamination in minimally processed fruits

Neste trabalho apresentamos uma metodologia bastante simples, fazendo uso de um sistema comercial de captura de imagens, composto de um scanner de mesa que combinado a um programa livre (freeware) da análise de imagens, permite estabelecer qualitativa e quantitativamente a evolução da infestação por fungos sobre frutos fatiados, sendo aqui avaliadas maçãs como exemplo. Penicillium sp e Alternaria sp. foram usados como contaminantes e as imagens geradas duas vezes ao dia empregadas para quantificação. A quitosana, um polissacarídeo com ação fungicida, foi empregado na forma de uma película invisível permitindo, assim, análises comparativas. O método, embora consideravelmente simples, mostrou-se útil sendo indicado para avaliação e prevenção de contaminações de micro-organismos em frutos minimamente processados.

[ comparison of the antimicrobial resistance pattern [antibiotyping] of staphylococcus strains isolated from orange and apple juices with the strains isolated from clinical samples, Shahrekord, Iran, 2007]

One of the main routes in which bacterial resistance is transmitted is through food products. Antibiotic products are widely used in the nature to control diseases. It has been shown that these products can be transmitted to human through meat, milk, fruit, fruit juices and water and consequently they can cause antibiotic resistance problems. The aim of this study was to compare antimicrobial resistance of staphylococcus strains isolated from orange and apple juices and those strains isolated from clinical samples. This descriptive- analytical study was performed on 111 staphylococcus bacteria which were isolated from fruit juices or from patients referring to the educational hospitals in Shahrekord, Iran. Antibiotic susceptibility test was performed by disc diffusion method. The bacteria were classified by antibiotyping. Data were analyzed using Fishers exact test. The results of antibiotyping showed that 111 staphylococcus isolates were distributed in 36 patterns from which 10 isolates [53%] were Staphylococcus aureus belonged to 4 patterns. From the total staphylococcus isolates, 62 isolates [67%], were Staphylococcus epidermidis which were belonged to 11 patterns. These patterns were observed the same in fruit juices and clinical samples [P>0.05]. The rest of isolates [39 isolates] were belonged to 21 patterns. The results of our study showed that most of the staphylococcus isolates were resistant to one or more antibiotics. On the other hand, 65% of isolated samples showed the same antibiotic resistance pattern in fruit juices and clinical samples. It is possible that food products, including fruit juices have role in transmitting bacterial resistance. Therefore, it is necessary to restrict the use of antibiotics and to control the production, transportation and maintenance of fruit juices

[Prevalence of bacterial contamination in orange and apple juices and correlation with some other factors in Shahrekord, 1385]

Fruit juices are becoming an important part of the modern diet among many communities. These juices can be contaminated with bacterial pathogens, leading to different gastrointestinal infections. This study was aimed to assess the prevalence of bacterial contamination in orange and apple juices and its correlation with some other factors. In this descriptive-analytical study, 360 apple and orange juice samples produced of three internal factories with less than six and more than six months of production were examined microbiologically, from August to December 2006 in Shahrekord. Data were analyzed by SPSS software, using Chi-square test. We found a rate of 4.4% contaminated fruit juices with a mean total isolated bacterial count [TBC] of 1.45 x10[3] cfu/ml. Isolated Bacteria included Staphylococcus epidermidis in 10 [62.5%], Staphylococcus aureus in 3 [19%], Bacillus subtilis in 2 [12.5%] and Bacillus cereus in 1 [6%] samples. Data analyses revealed no significant difference between contaminated samples and kind of fruit juices or factories [P>0.05]. However, a statistically significant difference was detected between contaminated samples and production time [P<0.01]. Based on our findings, we recommend consuming these products within six months of manufacturing as well as improving the maintenance and transporting conditions