Stability of fruit bases and chocolate fillings

Syrups with high sugar content and dehydrated fruits in its composition can be added to chocolate fillings to reduce the need of artificial flavor and dyes attributing a natural appeal to the product. Fruit bases were produced with lyophilized strawberry, passion fruit, and sliced orange peel. Rheological dynamic oscillatory tests were applied to determine the products stability and tendency of shelf life. Values of G´< G´´ were observed for strawberry and passion fruit flavor, whereas values of G´ > G´´ were found for orange flavor during the 90 days of storage. It was observed that shear stress values did not vary significantly suggesting product stability during the studied period. For all fillings, it was found a behavior similar to the fruit base indicating that it has great influence on the filling behavior and its stability. The use of a sugar matrix in fillings provided good shelf life for the fruit base, which could be kept under room temperature conditions for a period as long as one year. The good stability and storage conditions allow the use of fruit base for handmade products as well as for industrialized products.

Ascorbic acid and pectin in different sizes and parts of citric fruits

Citric fruits - in natura, as frozen pulp or even as juice - are one of the most important Brazilian exportation products. They are a source of ascorbic acid - a potent antioxidant, and pectin, which is used in the food industry and is an important dietary fiber. This project aims to quantify ascorbic acid and pectin contents in citric fruits, commercial oranges and tangerines, comparing them in sizes and varieties. Ascorbic acid amount was measured in juice comparing sizes, varieties and storage conditions, using a tritimetric method with 2.6-dichlorobenzenoindophenol indicator. Total and soluble pectin in each part of the fruits (peel, albedo, pulp and juice) were quantified using the polygalacturonic acid as a standard. Differences were found between the sizes. The highest content of vitamin C was found in the oranges (Bahia variety). Comparing the storage temperatures, the biggest loss was at room temperature. Albedo presented the highest content of pectin in all fruits. In juice, the total and soluble pectin contents increased as fruits size decreased. Oranges and tangerines differed in the amount of pectin

Comparison between the availability of iron in the presence of vitamin a and β-carotene in foods and medications

The objective of this work was to verify the availability of iron in the presence of vitamin A as components of foods and in combinations with medicines. The iron available was measured in the presence of vitamin A in foods - common bean (B), beef liver (Li) and carrot (C) - and medicines - Fer-In-Sol® (Fer) (Mead Johnson), Arovit® (A) (Roche) and Neutrofer® (N) (Sigma Pharma) - as well as in combinations of both. β-carotene, vitamin A, total iron, heme and non heme iron, percentage of dialyzable iron and amount of dialyzable iron was determined. Vitamin A and β-carotene had a positive effect on the percentage of iron dialysis. Carrot and liver had a better percentage of dialyzable iron than their respective medicine at similar concentrations. Therefore, we can conclude that there has been an influence of vitamin A over the dialysis of iron, being the mixtures containing liver the ones which achieved the highest concentrations of dialyzable iron, and also that, according to the amounts needed to obtain the daily recommended intake of iron, they are good for consumption.

Cooking quality of upland and lowland rice characterized by different methods

Rice cooking quality is usually evaluated by texture and stickiness characteristics using many different methods. Gelatinization temperature, amylose content, viscosity (Brookfield viscometer and Rapid Visco Analyzer), and sensory analysis were performed to characterize culinary quality of rice grains produced under two cropping systems and submitted to different technologies. All samples from the upland cropping system and two from the irrigated cropping system presented intermediate amylose content. Regarding stickiness, BRS Primavera, BRS Sertaneja, and BRS Tropical showed loose cooked grains. Irrigated cultivars presented less viscosity and were softer than upland cultivars. Upland grain samples had similar profile on the viscoamylografic curve, but the highest viscosity peaks were observed for BRS Alvorada, IRGA 417, and SCS BRS Piracema among the irrigated cropping system samples. In general, distinct grain characteristics were observed between upland and irrigated samples by cluster analysis. The majority of the upland cultivars showed soft and loose grains with adequate cooking quality confirmed by sensory tests. Most of the irrigated cultivars, however, presented soft and sticky grains. Different methodologies allowed to improve the construction of the culinary profile of the varieties studied.

Stability of volatile profile and sensory properties of passion fruit juice during storage in glass bottles

This study aimed at assessing the stability of passion fruit juice in glass bottles during a 120-day storage period, regarding its volatile compounds profile and sensory properties (aroma and flavor). Samples were obtained from a Brazilian tropical juice industry (Fortaleza, Brazil) and submitted to sensory and chromatographic analyses. The characteristic aroma and flavor of passion fruit were evaluated by a trained panel with a non-structured scale of 9 cm. The headspace volatile compounds were isolated from the product by suction and trapped in Porapak Q, analyzed through high-resolution gas chromatography and identified through gas chromatography-mass spectrometry (GC-MS). Twelve odoriferous compounds were monitored: ethyl butanoate, ethyl propanoate, 3-methyl-1-butanol, 3-methyl-2-butenol, (E)-3-hexenol, (Z)-3-hexenol, 3-methylbutyl acetate, benzaldehyde, ethyl hexanoate, hexyl acetate, limonene and furfural. The slight variations observed in the volatile profile were not enough to provoke significant changes in the characteristic aroma and flavor of the passion fruit juice.

Determination of presence and quantification of cadmium, lead and copper in Nile tilapia (Oreochromis niloticus) fillets obtained from three cold storage plants in the state of Parana, Brazil

Pisciculture is an economic activity that is steadily growing in the state of Parana, Brazil, and Nile tilapia (Oreochromis niloticus) is one of the widely cultivated species in this state. Tilapia is not only a very nutritious food, but also an important indicator of environmental contamination. This study aimed to verify contamination by cadmium, copper and lead in tilapia fillets, and to compare the found values to international legislations. Were collected 135 samples of tilapia fillets, between July 2006 and May 2007, in three fish stores located in regions west and north of Paraná State. Samples of tilapia fillet were analyzed in relation to the presence of cadmiun, lead and copper, using atomic absorption spectrophotometry. Lead has not been detected in the analyses. Cadmium has been detected in three samples, on concentrations of 0.012 µg.g-1, 0.011 µg.g-1 and 0.014 µg.g-1. Copper has been detected in all fillets, and the average concentration of each cold storage plant was of 0.122 µg.g-1, 0.106 µg.g-1 and 0.153 µg.g-1. The concentrations found in this study are within the limits allowed by both the European and the Australian legislations.

Color and chemical composition and of green corn produced under organic and conventional conditions

The present study aimed to evaluate the chemical properties of green corn, grown in both organic and conventional farming systems, using a completely randomized factorial design. Four corn varieties (AG 1051, BR 106, SWB 551 and VIVI) of green corn kernels were evaluated for color, proximate composition, total calories, carotenoids and bioactive amines. The farming system affected some chemical and physical characteristics of green corn, but this effect was dependent upon variety. In general, organic green corn kernels were reddish (a* color component) and had higher levels of β-carotene compared to the conventional ones, suggesting that these characteristics are related. Moreover, organic green corn had higher levels of total carbohydrates and total energy compared to conventional varieties. On the other hand, crude fiber levels were higher in conventional grains - an unexpected result that deserves further investigation. Finally, the levels of cadaverine and spermine bioactive amines were not affected either by the corn variety or by the farming system.

Phase transitions in biodegradable films based on blends of gelatin and poly (vinyl alcohol)

The aim of this work was to study the effect of the hydrolysis degree (HD) and the concentration (C PVA) of two types of poly (vinyl alcohol) (PVA) and the effect of the type and the concentration of plasticizers on the phase properties of biodegradable films based on blends of gelatin and PVA, using a response-surface methodology. The films were made by casting and the studied properties were their glass (Tg) and melting (Tm) transition temperatures, which were determined by diferential scanning calorimetry (DSC). For the data obtained on the first scan, the fitting of the linear model was statistically significant and predictive only for the second melting temperature. In this case, the most important effect on the second Tm of the first scan was due to the HD of the PVA. In relation to the second scan, the linear model could be fit to Tg data with only two statistically significant parameters. Both the PVA and plasticizer concentrations had an important effect on Tg. Concerning the second Tm of the second scan, the linear model was fit to data with two statistically significant parameters, namely the HD and the plasticizer concentration. But, the most important effect was provoked by the HD of the PVA.

Searching to combine technologies for safer food attainment

Campylobacteriosis is an infection frequently acquired through the consumption of animal origin products. Chicken can be considered the main responsible cause in the transmission chain of this disease. Ionizing radiation was used to verify the reduction of the microbiological load of Campylobacter jejuni present in chicken liver, which, in natura, can present contamination in up to 100% of the cases. The doses of irradiation used were: 0.20 kGy, 0.27 kGy, 0.30 kGy and 0.35 kGy. The samples of chicken liver were acquired in aviaries, local supermarkets and large chain supermarkets. The samples were analyzed for Campylobacter at FIOCRUZ. Irradiation was performed at COPPE/UFRJ, using a Gamma Cell Irradiator with a 60Co gamma source. Only the frozen sample acquired at the local supermarket did not contain the bacterium. Campylobacter sp. was present in all other samples, even when using procedures and technologies that aimed at the impediment of the presence of this bacterium in food and, consequently, at the protection of human health. On the whole, the results were satisfactory; nevertheless, it is known that the bacterial growth conditions required by this bacterium are uncommon when compared to other enteropathogenic bacteria.

Cassava starch in the Brazilian food industry

Cassava starch is a valued raw material for producing many kinds of modified starches for food applications. Its physicochemical properties, as well as its availability, have made it an interesting and challenging ingredient for the food industry. In the present work, food grade modified cassava starches were purchased from producers and analyzed for selected physicochemical characteristics. Samples of sour cassava starch were included, as well as one sample of native cassava starch. Results showed that almost all modified starches were resistant to syneresis, produced pastes more stable to stirred cooking, and some of them were difficult to cook. The sour cassava starches presented high acidity and resulted in clear and unstable pastes during stirred cooking, susceptible to syneresis.

Chemical and sensory characteristics of pulp and peel 'cajá-manga' (Spondias cytherea Sonn.) jelly

Cajá-manga (Spondias cytherea) is a fruit with intense aroma and a sweet sour taste, thus being very appreciated. Its peel, in spite of being more fibrous, is tender and many times consumed with the pulp. The peel is a part of foods normally discarded, but many times, it is rich in taste and fibers, representing an option at the elaboration of new foods. Since there are no reports in the literature on the use of cajá-manga peel for jelly making, this work had the purpose of developing and evaluating this product. Based on the results, it was noted that the peels presented higher contents of protein, lipids, ashes, food fiber, total carbohydrates and pectin, and lower content of moisture, when compared to the pulp. The peel and the pulp (control) jellies presented the following physical-chemical characteristics: moisture, 29.5 and 34.2%; proteins, 0.19 and 0.27%; lipids, 0.11 and 0.16%; total sugars, 56.5 and 65.5%; and total soluble solids, 69 and 66 ºBrix, respectively. The sensory analysis indicated that the product elaborated from the peel presented satisfactory acceptance for all the assessed attributes: appearance, color, odor, texture, taste and global evaluation. It is concluded that the total substitution of the pulp by the peel in the formulation, results in a product with good nutritional value with no sensory damages.

Determination of pectin methylesterase activity in commercial pectinases and study of the inactivation kinetics through two potentiometric procedures

Pectinases are enzymes that degrade pectic substances and are widely used in juice and fruit beverages to improve the quality of the process. The objective of this study was to determine the optimum pH and temperature of two samples of commercial pectinases and propose an alternative procedure to determine the residual activity comparing the data with those of the traditional procedure. The pectin methylesterase (PME) activity in Pectinex 100 L Plus and Panzyn Clears was determined by potentiometry. The reaction consisted of 5.00 mg.mL-1 apple pectin, 0.100 mol.L-1 NaCl, and 50 µL enzyme to a total volume of 30 mL. The pectin reaction in the presence of PME in all experiments revealed a first order kinetics. The PME in the two enzyme preparations showed higher activity at pH 4.0 to 4.5 and temperature of 45 ºC. From the results of both procedures ΔV NaOH/Δt and ΔpH/Δt, it was concluded that the inactivation of PME occurred at 75 ºC. The results obtained from the ratio ΔpH/Δt showed good correlation with those obtained from the ratio ΔV NaOH/Δt. In the reaction accompanied by the ratio ΔpH/Δt, the release of H3O+ occurred in the real time reaction.

Chemical pattern of brazilian apples: a chemometric approach based on the Fuji and Gala varieties

The chemical composition of apple juices may be used to discriminate between the varieties for consumption and those for raw material. Fuji and Gala have a chemical pattern that can be used for this classification. Multivariate methods correlate independent continuous chemical descriptors with the categorical apple variety. Three main descriptors of apple juice were selected: malic acid, total reducing sugar and total phenolic compounds. A chemometric approach, employing PCA and SIMCA, was used to classify apple juice samples. PCA was performed with 24 juices from Fuji and Gala, and SIMCA, with 15 juices. The exploratory and predictive models recognized 88% and 64%, respectively, as belonging to a mixed domain. The apple juice from commercial fruits shows a pattern related to cv. Fuji and Gala with boundaries from 0.18 to 0.389 g.100 mL-1 (malic acid), from 8.65 to 15.18 g.100 mL-1 (total reducing sugar) and from 100 to 400 mg.L-1 (total phenolic compounds), but such boundaries were slightly shorter in the remaining set of commercial apple juices, specifically from 0.16 to 0.36 g.100 mL-1, from 9.25 to 15.5 g.100 mL-1 and from 180 to 606 mg.L-1 for acidity, reducing sugar and phenolic compounds, respectively, representing the acid, sweet and bitter tastes.

Volatile compounds from organic and conventional passion fruit (Passiflora edulis F. Flavicarpa) pulp

The volatile compositions from organic and conventional passion fruit pulps produced in Brazil were investigated. The pulps were also physicochemically characterized. The volatile compounds from the headspace of the passion fruit pulp were stripped to a Porapak Q trap for 2 hours; they were eluted with 300 µL of dichloromethane, separated by gas chromatography/flame ionisation detection and identified through gas chromatography/mass spectrometry. Both pulps conformed to the requirements of the Brazilian legislation, indicating they were suitable to be industrialized and consumed. A total of 77 compounds were detected in the headspace of the passion fruit pulps - 60 of which were identified, comprising 91% of the total chromatogram area. The major compounds were the following: ethyl butanoate, 52% and 57% of the total relative area of the chromatogram for the organic and conventional passion fruit pulps, respectively; ethyl hexanoate, 22% and 9%, respectively; and hexyl butanoate, 2% and 5%, respectively. The aroma of the organic passion fruit pulp is mainly related to the following volatile compounds: ethyl hexanoate, methyl hexanoate, β-myrcene and D-limonene. The conventional passion fruit pulp presented methyl butanoate, butyl acetate, hexanal, 1-butanol, butyl butanoate, trans-3-hexenyl acetate, cis-3-hexen-1-ol, butyl hexanoate, hexyl butanoate, 3-hexenyl butanoate and 3-hexenyl hexanoate as the main volatile compounds for aroma.

Lipid and protein oxidation in the internal part of italian type salami containing basil essential oil (Ocimum basilicum L.)

Different concentrations of basil essential oil (Ocimum basilicum L.) (0.19; 0.38; 0.75; 1.87; 3.75 and 6.00 mg.g-1) were evaluated in relation to their antioxidant activity using the DPPH● radical methodology. From the IC50 obtained data, the concentrations of 0.19; 0.38; 0.75; 1.87; 3.75; 6.00 and 12.00 mg.mL-1 were applied directly to the product and these were sensorially evaluated by the test of control difference. The concentrations related to the highest acceptability (0.19; 0.38 and 0.75 mg.g-1) were tested for antioxidant activity in the internal part of Italian type salami - during the processing and after 30 days of storage, in terms of lipid and protein oxidation. The oxidation of lipids was determined using the method of TBARS. The method of carbonyl compounds was employed for proteins oxidation. Five different formulations of salami were elaborated: blank (without the use of antioxidant); control (using sodium eritorbate as antioxidant); and adding 0.19; 0.38 and 0.75 mg.g-1 of basil essential oil. The product was kept between 25 ºC and 18 ºC and UR between 95% and 70%, for 28 days. Analyses were carried out on the processing day and after 2, 7, 14, 21 and 28 days, and also following 30 days of storage. The basil essential oil in vitro presented an antioxidant activity of IC50 12 mg.mL-1. In the internal part of the Italian type salami the commercial antioxidant (control) and the formulation containing 0.75 mg.g-1 of basil essential oil presented antioxidant activity in relation to the lipids, but not to the proteins - during processing and storage.