Use of mathematical models for estimating the shelf-life of cornflakes in flexible packaging

The objective of this work was to evaluate three different mathematical models (linear, middle point and logarithm interval) to predict the stability of commercial cornflakes in flexible packages. The limiting factor for cornflakes' shelf-life was gain of moisture from the external environment, which caused loss of crispness and thus was unacceptable to the consumer. It was concluded that both middle point and logarithm interval methods are suitable for estimating the stability of cornflakes with a good approximation. The accuracy of these two methods depends on the precision of the experimental points of the sorption isotherms. The best fit to adjust the moisture isotherm was the GAB model. Knowledge of the mode of deterioration of the product and the sensory critical moisture content were fundamental to understanding and setting up the limits to confirm the models. Copyright (c) 2005 John Wiley & Sons, Ltd.18417117

Evaluation of a system for chemical sterilization of packages

A system was evaluated for the chemical sterilization of packages, based on its sporicidal efficiency using inoculated Bacillus subtilis inside polyethylene terephthalate (PET) bottles. Different combinations of contact time, temperature and peracetic acid concentrations were tested, delineated according to a factorial planning of 2(3). The results, expressed as decimal reduction counts, proved that peracetic acid showed good sporicidal efficiency at 1.2% concentration in the temperature range 30-50degreesC. With this performance, the tested system can be used to sterilize plastic bottles and other similar packages, achieving a count reduction of spores by up to 10(-7). Copyright (C) 2004 John Wiley Sons, Ltd.171374

The efficiency of TBHQ, beta-carotene, citric acid, and tinuvin 234 (R) on the sensory stability of soybean oil packaged in PET bottles

The use of plastic packaging for oils permits exposure to light, increasing oxidation. The goal of this work was to maximize sensory stability of soybean oil packaged in PET bottles. A central composite design was used to combine different levels of TBHQ, beta-carotene, and citric acid, added to oil, and Tinuvin 234(R), added to bottles. After 6 mo of storage, the oxidation degree was assessed by sensory and peroxide tests. TBHQ and Tinuvin 234 were the most effective antioxident, and the minimum concentrations required to keep a reasonable stability during storage were: 120 ppm of TBHQ; 7 ppm of beta-carotene; 15 ppm of citric acid and 0.1% of Tinuvin 234.68130230

Bacillus cereus in Refrigerated Milk Submitted to Different Heat Treatments

The possibility of the survival, germination, and multiplication of Bacillus cereus in extended-shelf-life milk prompted research into the occurrence of the bacteria in refrigerated milk submitted to different heat treatments. Samples were submitted to ultrapasteurization (138 degrees C for 2 s), "superpasteurization" (96'degrees C for 13 s), and pasteurization (74 degrees C for 15 s) and stored under refrigeration at 4 +/- 2 degrees C for up to 6 weeks. The milk was analyzed for its sensory quality and for the quantitative determination of mesophilic and psychrotrophic B. cereus in the vegetative form at incubation temperatures of`7 and 30 degrees C, in addition to standard plate Counts and psychrotrophic counts. In the three experimental trials, the psychrotrophic B. cereus counts were below the detection limit of the methodology (<10 CFU/ml) in all of the samples analyzed, independent of the heat treatment and storage period. The count of mesophilic B. cereus was restricted to samples of superpasteurized and pasteurized milk from a single trial, reaching 4.0 x 10(1) and 7.0 x 10(5) CFU/ml, respectively. Although the pasteurized milk had higher populations of mesophilic B. cereus after the second week of storage, flavor defects resulting in sensory rejection of the product did not appear before the fourth week of storage. The results of this research indicate that superpasteurization and ultrapasteurization are adequate for maintaining the product at refrigeration temperatures for 6 weeks. Pasteurized milk produced under clean conditions should have a shelf life limited to less than 2 weeks.7261301130

The influence of sweeteners in probiotic Petit Suisse cheese in concentrations equivalent to that of sucrose

As in the case of probiotic functional foods in recent years, demand has increased notably for light or diet foods with added sweeteners. However, little is known about the effect of different sweeteners on the microorganisms present. Thus, the objective of the current study was to establish the ideal sucrose concentration and equivalent concentrations of different sweeteners and to determine, by microbiological analyses, the influence of these compounds on the viability of the starter and probiotic cultures used in the production of strawberry-flavored Petit Suisse cheese during its shelf life. The ideal sucrose concentration was determined using the just-about-right (JAR) scale, and the equivalent concentrations of the sweeteners were subsequently determined by the magnitude estimation method. Microbiological analyses were also carried out to check the viability of the cultures during the product's shelf life. The results showed that the compounds Neotame (NutraSweet, Chicago, IL) and stevia presented, respectively, the greatest and least sweetening power of the sweeteners tested. None of the sweeteners used in this study exerted a negative effect on the viability of the starter or probiotic cultures, and thus we were able to obtain a probiotic, functional food with reduced calorie content.9695512552

Effect of addition of CO2 to raw milk on quality of UHT-treated milk

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The objective of this study was to evaluate the effect of addition of CO2 to raw milk on UHT milk quality during storage. Control milk (without CO2 addition) and treated milk (with CO2 addition up to pH 6.2) were stored in bulk tanks at 4 degrees C for 6 d. After storage, both samples were UHT processed using indirect heating (140 degrees C for 5 s). Samples were aseptically packed in low-density polyethylene pouches and stored in the dark at room temperature. Raw milk was evaluated upon receipt for physicochemical composition, proteolysis, lipolysis, standard plate count, psychrotrophic bacteria, and Pseudomonas spp. counts, and after 6 d of storage for proteolysis, lipolysis, and microbial counts. After processing, UHT milk samples were evaluated for physicochemical composition, proteolysis, and lipolysis. Samples were evaluated for proteolysis and lipolysis twice a month until 120 d. Peptides from pH 4.6-soluble N filtrates were performed by reversed-phase HPLC after 1 and 120 d of storage. A split-plot design was used and the complete experiment was carried out in triplicate. The results were evaluated by ANOVA and Tukey's test. After 6 d of storage, CO2-treated raw milk kept its physicochemical and microbiological quality, whereas the untreated milk showed significant quality losses. A significant increase in proteolysis occurred during 120 d of storage in both treatments, but the increase occurred 1.4 times faster in untreated UHT milk than in CO2-treated UHT milk. In both UHT milks, the proteolysis was a consequence of the action of plasmin and microbial proteases. However, the untreated UHT milk showed higher microbial protease activity than the treated UHT milk. The addition of CO2 to the raw milk maintained the quality during storage, resulting in UHT milk with less proteolysis and possibly longer shelf life, which is usually limited by age gelation of UHT milk.95842564262Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Food allergens: Knowledge and practices of food handlers in restaurants

This survey evaluated the knowledge of managers and food handlers, who work in restaurants functioning in two large supermarket chains in the metropolitan region of the city of Sao Paulo (Brazil), concerning food allergies. Twelve restaurants were evaluated, representing a total of 74 people (12 managers and 62 food handlers). Results have shown that even though the survey showed that food handlers had some knowledge on food allergies, allergic people must stay on the alert, questioning the place where they are going to have their meals in terms of the ingredients used, verifying whether the food is really free of allergens, and always observing the labels of food products. This is needed since there is no real concern by these establishments in preparing safe meals in terms of food allergies. (C) 2010 Elsevier Ltd. All rights reserved.21101318132

Survival analysis methodology to predict the shelf-life of probiotic flavored yogurt

The feasibility of survival analysis methodology was used to determine the shelf-life of probiotic strawberry flavored yogurt supplemented with Bifidobacteirum animalis DN 173010 W was investigated. The quality parameters of probiotic yogurts were related to storage conditions which they are submitted. The consumers were shown sensitive to changes towards sensory characteristics introduced into the products. Using the survival analysis and considering 25% and 50% probability of consumer rejection, the shelf-life of the probiotic yogurt was estimated at 38 and 53 days, respectively. The findings of this research highlighted the feasibility this technique to determine the shelf-life of foods, in particular, functional foods, as probiotic yogurts. (C) 2010 Elsevier Ltd. All rights reserved.4351444144

Short communication: Effects of different whey concentrations on physicochemical characteristics and viable counts of starter bacteria in dairy beverage supplemented with probiotics

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fermented dairy beverages supplemented with the probiotics Lactobacillus acidophilus and Bifidobacterium lactis containing different concentrations of whey in their formulas (0, 20, 35, 50, 65, and 80%, vol/vol) were processed and checked for pH; proteolysis; levels of glucose, lactose, ethanol, acetic acid, lactic acid, diacetyl, and acetaldehyde; and lactic bacteria and probiotic counts. The results allowed the effect of whey concentration on the dairy beverages to be observed for each of the different parameters analyzed. The degree to which the whey concentration was useful for the microbial cultures, particularly probiotic cultures, appeared to have a limit. In general, dairy beverages processed with different levels of whey in their formulation exhibited good potential as a food matrix for supplementation with probiotic bacteria, with production of characteristic compounds of fermented milk products, such as volatiles and organic acids.96196100Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAEPEX/UNICAMP (Fundo de Apoio ao Ensino, a Pesquisa e Extensao)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Viability of probiotic bacteria in fermented skim milk produced with different levels of milk powder and sugar

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)In this work, the effect of skim milk powder (0, 5%, 10%, 15% w/v) and sugar (0%, 10% w/v) on the viability of probiotic micro-organisms and on the quality of fermented milks was investigated. Fermented milks were submitted to physicochemical, microbiological and sensory analyses on the 1st, 10th and 21st days after production. Sugar inclusion did not affect the probiotic growth in fermented milks, but milk powder levels of 10-15% influenced positively the probiotic counts, which were above six log colony-forming units (cfu)/g. These findings can be useful for small dairy industries that are interested in producing flavoured fermented milks without decreasing the viability of probiotic micro-organisms during its shelf life.6718994Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2007/06353-1