Positive samples were tested for the production of lipolytic and proteolytic enzymes. Microorganisms of the genus Pseudomonas were isolated from all sampling points. A higher isolation rate of the bacterium was found in the rainy season except for 6 sampling points, with all of these associated with mechanical milking systems. Pseudomonas spp. exhibiting lipolytic activity were found to be predominant during the dry season, since no activity was detected during the rainy season in 26 of the 29 sampling sites. The highest number of lipolytic Pseudomonas isolates was obtained from water. Presence of lipase-producing Pseudomonas spp. was verified in 7 and 36% of the samples collected from farms with manual and mechanical milking, respectively. When analyzing raw milk collected from expansion tanks immediately (0 h) and 24h after milking, we observed that for dairy properties with manual milking process, 10% of the Pseudomonas isolates were positive for lipolytic activity. The percentage increased to 12% 48h after milking. Mean averages were 32, 33, and 39% immediately after, 24 and 48h after milking, respectively, for farms with mechanical milking. All sampling points showed the presence of proteolytic strains of Pseudomonas. The highest proteolytic activity was found during the rainy season, except for the samples collected from milkers' hands before milking, buckets, and teat cup inner surfaces after milking and from the water in dairy farms with mechanical milking system. Of these samples, 72, 56, and 50%, respectively, were positive for proteolysis during the dry season. For the water samples, a statistical difference was observed between mechanical (50%) and manual (7%) milking systems in the percentage of proteolytic activity. No production of proteolytic enzyme was detected in the samples from milkers' hands taken after milking and no statistically significant difference was found among manual (19.91%) and mechanical (47.85%) milking. During the rainy months, no proteolysis was detected in the samples taken from cows' teats after the predipping. It is evident, therefore, that preventive measures capable of minimizing the contamination with Pseudomonas spp. during milking and storage of refrigerated raw milk are needed, regardless of season.
The species of the Bacillus cereus group have the ability to adhere to and form biofilms on solid surfaces, including stainless steel, a material widely used in food industries. Biofilms allow for recontamination during food processing, and the “clean-in-place” (CIP) system is largely used by industries to control them. This study thus proposes to evaluate the efficacy of peracetic acid and sodium hypochlorite against biofilms induced on stainless-steel surfaces. The SAMN07414939 isolate (BioProject PRJNA390851), a recognized biofilm producer, was selected for biofilm induction on AISI 304 stainless steel. Biofilm induction was performed and classified into three categories: TCP (Tindalized, Contaminated, and Pasteurized milk), TCS (Tindalized milk Contaminated with Spores), and TCV (Tindalized milk Contaminated with Vegetative cells). Subsequently, the coupons were sanitized simulating a CIP procedure, on a pilot scale, using alkaline and acid solutions followed by disinfectants (peracetic acid and sodium hypochlorite). Microorganism adhesion on the surfaces reached 6.3 × 105 to 3.1 × 107 CFU/cm-2. Results did not show significant differences (p > 0.05) for surface adhesion between the three tested categories (TCP, TCS, and TCV) or (p > 0.05) between the two disinfectants (peracetic acid and sodium hypochlorite). Microbial populations adhered to the stainless-steel coupons are equally reduced after treatment with peracetic acid and sodium hypochlorite, with no differences in the control of B. cereus s.s. biofilms on AISI 304 stainless-steel surfaces.
Spore forming bacteria can play an important role in food quality and safety as spoilage and pathogenic microorganisms due to resistance to heat-treatment. However, there are limited number of studies focused on evaluate the microbiological quality and the occurrence of these bacteria in UHT goat milk, soymilk and dairy beverage of goat milk and soy protein. On this context, 75 samples of these beverages were evaluated regarding heterotrophic mesophilic microorganisms by conventional plate count and selective methods to detect microorganisms from Bacillus cereus group and Clostridium perfringens. Population counts greater than 10 4 CFU.ml-1 of heterotrophic mesophilic microorganisms were observed in 80% of the lots of goat milk and 100% of the lots of soymilk and dairy beverage of goat milk and soy protein. The presence of bacteria belonging to B. cereus group was observed in 16%, 52% and 44% of goat milk, soymilk and dairy beverage of goat milk and soy protein, respectively. C. perfringens was isolated from 8% samples of UHT soymilk. The frequency of genes hblA, hblB, hblC, nheA, nheB, nheC in 29 isolates obtained from these products was 62%, 48.2%, 96.5%, 79.3%, 68.9% and 79.3%, respectively. The microbiological quality of the evaluated products was unsatisfactory.
(1) Background: People with ASD commonly present difficulty performing motor skills and a decline in physical activity (PA) level and low enjoyment of PA. We aimed to evaluate whether longitudinal practice of an activity in virtual and real environments improves motor performance and whether this improvement is transferred to a subsequent practice when changing the environment, promoting PA and providing enjoyment; (2) Methods: People with ASD, aged between 10 and 16 years, were included and distributed randomly into two opposite sequences. The participants performed a 10 session protocol, with five sessions practicing in each environment (virtual or real). Heart rate measurement was carried out and an enjoyment scale was applied; (3) Results: 22 participants concluded the protocol. Sequence A (virtual first) presented an improvement in accuracy and precision and transferred this when changing environment; they also had a greater change in heart rate reserve. The majority of participants reported “fun” and “great fun” levels for enjoyment; (4) Conclusions: The virtual reality activity presented a higher level of difficulty, with greater gains in terms of transference to the real environment. Considering PA, our task provided very light to light activity and the majority of participants enjoyed the task.
Anais do II Simpósio de Qualidade de Leite -SQL -(2014 -Jaboticabal -SP).
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