Prevention of enzymatic browning of yacon flour by the combined use of anti-browning agents and the study of its chemical composition

Yacon roots present functional properties because of the high levels of fructooligosaccharides (FOS), which are considered as prebiotic fibers. In addition, yacon roots are rich in phenolic compounds. During the processing of yacon, the freshly cut surface undergoes rapid enzymatic browning. Control of enzymatic browning during processing is very important to preserve the appearance of yacon flour. In this study, it was evaluated the combined effect of anti-browning agents (ascorbic acid, citric acid and L-cysteine) on the inhibition of enzymatic browning of yacon, using Response Surface Methodology. The yacon pre-treated with anti-browning agents in concentrations of 15.0 mM for ascorbic acid, 7.5 mM for citric acid and 10.0 mM for L-cysteine was used for the processing of flour. Yacon flour presented an attractive color and good sensory properties, without residual aroma. The contents of FOS and phenolic compounds obtained in yacon flour were 28.60 g.100 g- 1 and 1.35 g.100 g- 1. Yacon flour can be considered as a potential functional food, especially due to high levels of FOS, which allows for its use in formulation of various foods.

Preliminary studies on nutritive and organoleptic properties in processed fish fillets obtained from Iran

The effects of boiling, frying, and roasting methods on nutrients and properties some of marine fishes were studies. AOAC official methods were used for the analyses of the samples. Frying reduced the protein content of Nemipterus japonicas, while roasting reduced the protein content of Carangoides malabaricus and Saurida undosquamis. Fresh and fried C. malabaricus had 71.2% and 57.05% protein content, respectively, while N. japonicas had 57.39% and 47.51%, respectively. The highest oil content in C.malabaricus was 16.80%, followed by N.japonicus 12.80%; while the lowest oil content in S.undosquamis was 5.88%. N.japonicusis protein content reduced with frying. Some cooking methods used in the processing can have an effect on of fish nutrient composition. The texture of fried and boiled fish fillets significantly differ from that of the roasted fillets (p<0.05).

Bioactive compounds and acceptance of cookies made with Guava peel flour

The use of fruit industrial waste in the processing new foods represents an important new step for the food industry. This study aimed to develop cookie recipes using different amounts of guava peel flour (GPF) levels (30%, 50%, and 70%) to evaluate the proximate composition, and the phenolic compound, lycopene, and β-carotene levels in the cookies and flour and to evaluate the cookie sensory acceptance. The results demonstrated low moisture, lipid and carbohydrate contents in the flour and cookies. GPF was considered rich in fiber, ash, polyphenols, and β-carotene. The sensory analysis showed satisfactory acceptance of the cookies containing 30% GPF regarding the aroma, flavor, and texture attributes. The cookies containing 50% and 70% GPF received satisfactory acceptance regarding to aroma only. In conclusion, GPF can be used to partially replace wheat flour in the preparation of cookies to improve the nutritional quality without affecting the product sensory quality.

Chemical characterization of the flour of peel and seed from two papaya cultivars

Papaya is among the currently most important tropical fruits grown in Brazil and in the world. The fruit is mainly consumed fresh although it offers many industrial products. The processing of this fruit, as well as its fresh consumption, results in large amounts of waste, such as peels and seeds. Papaya consumption is one of the causes of significant loss of food value; therefore, new aspects on the use of its waste as by-products, or in the production of food additives, or even the incorporation of its flour in food have aroused great interest because these are products of high nutritional value, and their use may be economically viable. The objective of this study was to produce and characterize peel and seed flours from two papaya cultivars (Havai and Calimosa) for their chemical constituents focusing on possible use in foods. The proximate and mineral composition, titratable acidity, soluble solids, pH, contents of vitamin C, and phenolic compounds were determined. According to the results obtained, the papaya peel and seed flours had high contents of protein and fiber and therefore can be used as alternative sources of nutrients and can also be added in foods avoiding waste and adding value to the fruit.

Chemical composition, fatty acid profile and bioactive compounds of guava seeds (Psidium guajava L.)

This study aimed to characterize the chemical composition, determine the fatty acid profile, and quantify the bioactive compounds present in guava seed powder (Psidium guajava L.). The powder resulted from seeds obtained from guava pulp processing. The agro-industrial seeds from red guava cv. paluma were used, and they were donated by a frozen pulp fruit manufacturer. They contain varying amounts of macronutrients and micronutrients, with a high content of total dietary fiber (63.94 g/100g), protein (11.19 g/100g), iron (13.8 mg/100g), zinc (3.31 mg/100g), and reduced calorie content (182 kcal/100g). Their lipid profile showed a predominance of unsaturated fatty acids (87.06%), especially linoleic acid (n6) and oleic acid (n9). The powder obtained contained significant amounts of bioactive compounds such as ascorbic acid (87.44 mg/100g), total carotenoids (1.25 mg/100 g) and insoluble dietary fiber (63.55 g/100g). With regard to their microbiological quality, the samples were found suitable for consumption. Based on these results, it can be concluded that the powder produced has favorable attributes for industrial use, and that use of these seeds would be a viable alternative to prevent various diseases and malnutrition in our country and to reduce the environmental impact of agricultural waste.

Biochemical and color changes of fresh-cut melon (Cucumis melo L. cv. Galia) treated with UV-C

The importance of minimally processed commodities in the retail groceries of most developed countries has been rising continuously during the last decades. Cantaloupe melon is used more than any other fruit in fresh-cut processing. Ultraviolet (UV) light has been extensively used to simulate biological stres in plants and for determining resistance mechanisms of plant tissues. In this study the effect of ultraviolet irradiation on some properties of fresh-cut cantalope melon was determined during storage. Freshly cut cantalope melons cubes treated with ultraviolet irradiation at the doses of 1, 2 or 3 min before storage, and then placed in a cold room at 5±1°C temperature and 85-90% RH. Hue angle values of control group is low compared to UV-C treated samples, whereas L values of is high. EL of UV treated samples higher than those of control group. Total soluble solids of fresh-cut melon samples in UC3 treatment increased during storage. The results indicate that UV-C treatments on fresh-cut cantaloupe melon cubes increased total soluble solids independently from water loss.

Physicochemical and sensory characteristics of snack made with minced Nile tilapia

Nile tilapia is one of the major fish species cultivated worldwide and in Brazil. The tilapia fillet yield is between 30-35%, thus around 70% of waste is generated. A portion of this waste can be used to obtain minced fish, and the resulting product can be used as meat raw material to prepare fish snacks. The aim of this study was to produce fish snacks containing different inclusion levels (20, 30, and 40%) of minced fish obtained from Nile tilapia processing waste and evaluate their physicochemical characteristics and sensory acceptance. Protein content, ash, water activity, and hardness increased with increasing inclusion of minced fish. The scores obtained in the sensory evaluation were: flavor acceptance (from 7.2 to 5.7), texture (from 7.4 to 5.3), overall acceptance (from 7.1 to 5.9), and willingness to purchase (from 4.0 to 3.1). This study demonstrates that the inclusion of 20 to 40% of minced fish of Nile tilapia in snacks is well accepted and improves their nutritional value without affecting the physicochemical properties.

Evaluation of allicin stability in processed garlic of different cultivars

This research aimed at evaluating the suitability of five different garlic cultivars for the processing of unsalted garlic paste, chopped fried garlic, and fried sliced garlic. The concentration of allicin in the products was evaluated immediately after processing and at 45-day intervals during 180 days of storage. Allicin concentrations in raw garlic of the varieties under study differed (20.73 a 24.31mg of allicin g- 1 garlic). Stability exhibited a similar between the varieties according to the type of processing utilized. Processing into paste was more favorable to the preservation of allicin than the other processes. The amount of allicin lost during the process to obtain paste for the different varieties was less than 9.5%, and it reached a maximum loss of 22% for the commercial varieties during storage (180 days). All fried garlic samples showed a decrease by 99% in the content of allicin right after processing. The processing of garlic in the form of acidified paste preserved its bioactive characteristics during storage.

Application of enzymatic preparations to produce araçá pulp and juice

In the present study, the effect of pectinases on the production of pulp and juice of araçá and the presence of bioactive compounds were evaluated. An enzyme extract (EE) produced by Aspergillus niger LB-02-SF in solid state fermentation and the commercial enzyme Ultrazym®AFP-L were used in this study. After enzyme treatment with the EE preparation, the extraction yield increased by 23.1% and viscosity decreased by 42.8%, during pulp maceration. During juice processing, there was an increase of 70.6% in clarification and a decrease of 72.87% in turbidity. Higher values of these parameters, 47.7, 69.0, 80.7, and 79.7%, respectively, were obtained using the Ultrazym®AFP-L, which also led to a significant increase in the polyphenol content, both in the pulp (24%) and in the juice (28%), with a less pronounced effect when the EE was applied (10 and 21%, respectively). The anthocyanins content in the araçá pulp increased after treatment with the commercial preparation (23%), and there was no significant increase with the use of EE. The use of Ultrazym®AFP-L increased the β-carotene content by 29.4% in the fruit pulp, while the treatment with EE did not result in significant changes compared with those of the juice and pulp controls.

Characterization of blueberry fruits (Vaccinium spp.) and derived products

The objectives of this study were to physicochemically characterize and determine the antioxidant activities and anthocyanin contents of organic Rabbiteye blueberries grown in Southern Brazil and its derived products, in order to investigate the utility of food processing wastes as raw materials for developing products with beneficial health properties. The antioxidant capacity of the blueberries was superior to that of other fruits and juices. The pomace exhibited high activity, albeit lower than that of the fruit, while the flour and the dried blueberries lost 66% and 46% of the original antioxidant activity, respectively. The average anthocyanin contents of the fruits were moderate compared to other sources and species of blueberries. The pomace contains a large amount of anthocyanins while the flour and dried blueberries exhibited a 32% and 42% loss in anthocyanin content, respectively. The use of agro-industrial residues, in addition to adding value and minimizing the impact caused by the accumulation in the environment, can be directed toward the development of new products with bioactive properties.

Survival of Shiga toxin-producing Escherichia coli O157:H7 in Minas frescal cheese

Shiga toxin-producing Escherichia coli (STEC) O157:H7 strains (isolated by cattle’s faeces and a reference strain, EDL933), were inoculated into pasteurized milk (102 and 103 cells.mL–1) to prepare the Minas frescal cheese. As control was used uninfected milk. Physicochemical and microbiological analyses were performed to milk and elaborated cheese. The O157:H7 strains were quantified in the stages of cheese processing and during 0, 2, 4, 5, 7, 10 and 15 storage days at 8 °C onto Sorbitol MacConkey Agar supplemented with potassium tellurite and cefixime (CT-SMAC). O157:H7 was not present in the pasteurised milk prior to the artificial inoculation. At the end of the processing the cheese had 10 to 100 times more STEC O157:H7 than the initial inoculum. During the storage, the Minas frescal cheese exhibited the largest population increase on the 4th and 5th day when inoculated with 102 and 103 cells.mL–1, respectively. Additionally, viable cells were found up to the 10th and 15th day, according to the amount of initial inoculum. This number of cells is able to cause infection in humans, and therefore, Minas frescal cheese, even when stored under refrigeration, is a potential vehicle of disease caused by STEC O157:H7.

Bioactive compounds in different cocoa (Theobroma cacao, L) cultivars during fermentation

One component that contribute to the flavor and aroma of chocolate are the polyphenols, which have received much attention due to their beneficial implications to human health. Besides bioactive action, polyphenols and methylxantines are responsible for astringency and bitterness in cocoa beans. Another important point is its drastic reduction during cocoa processing for chocolate production and the difference between cultivars. Thus, the present study aimed to evaluate the modifications in monomeric phenolic compounds and methylxanthines during fermentation of three cocoa cultivars grown in southern Bahia. Cocoa beans from three cultivars were fermented and sun dried and monomeric phenolic compounds and methylxantines were determinated. The results showed that each cultivar have different amounts of phenolic compounds and the behaviour of them is different during fermentation. The amount of methylxantines varied but there was not a pattern for methylxantines behavior during process. In addition a huge reduction in phenolic compounds could be observed after drying. Differently of phenolic compounds, methylxantines did not have great modification after sun drying. So, the differences observed in this study between cultivars, take to the conclusion that the compounds studied in those cocoa cultivars have different behavior during fermentation and drying, which consequently, give to these cultivars differences in sensory characteristics.

Annatto seed residue (Bixa orellana L.): nutritional quality

Considering that annatto seeds are rich in protein, the present work aimed to evaluate the biological quality of this nutrient in the meal residue originating from annatto seed processing. We determined the general composition, mineral levels, amino acid composition and chemical scores, antinutritional factors, and protein quality using biological assays. The following values were obtained: 11.50% protein, 6.74% moisture, 5.22% ash, 2.22% lipids, 42.19% total carbohydrates and 28.45% fiber. The residue proved to be a food rich in fiber and also a protein source. Antinutritional factors were not detected. The most abundant amino acids were lysine, phenylalanine + tyrosine, leucine and isoleucine. Valine was the most limiting amino acid (chemical score 0.22). The protein quality of the seed residue and the isolated protein showed no significant differences. The biological value was lower than that of the control protein but higher than that found in other vegetables. Among the biochemical analyses, only creatinine level was decreased in the two test groups compared to the control group. Enzyme tests did not indicate liver toxicity. The results showed favorable aspects for the use of annatto seed residue in the human diet, meriting further research.

Optimization of microwave drying conditions of two banana varieties using response surface methodology

AbstractOptimization of microwave drying conditions of Luvhele and Mabonde banana varieties were studied using response surface methodology. The drying was performed using a central composite rotatable design for two variables: microwave power level (100, 200 and 300 W) and drying time (40, 26, and 12 min.) for Luvhele; (100, 200 and 300 W) and (42, 27, and 12 min) for Mabonde. The colour and texture (hardness) data were analyzed using ANOVA and regression analysis. The fitness of the models obtained was good as the lack of fit for each of the models was not significant. The coefficient of determination R2 of the models was relatively high, hence the models obtained for the responses were adequate and acceptable. Drying conditions of 178.76 W, 12 min. drying time were found optimum for product quality at a desirability of 0.91 for Luvhele; while 127.67 W, 12 min. with a desirability of 0.86 was predicted for Mabonde. The result of this study could be used as a standard for microwave processing of Luvhele and Mabondebanana varieties.

Effect of huitlacoche (Ustilago maydis DC Corda) paste addition on functional, chemical and textural properties of tortilla chips

AbstractThis study analyzed the addition of huitlacoche paste (HP) in baked tortilla chips (TC), evaluating its effects on functional, physicochemical and structural changes during processing. Two blue corn grains were nixtamalized, stone milled, air dried and milled to obtain flour; commercial blue corn flour (TM1) and commercial TC (TM2) were used as controls. Additions of 0, 3, 6 and 9% of HP were formulated; masas were prepared at 55% moisture content (MC), precooked and baked in an industrial machine. TC crispiness was influenced by grain characteristics and percentage of HP. Huitlacoche paste addition caused an increase in total dietary fiber (from 5.27 to 14.54%), total soluble phenolics content (from 17.52 to 37.60 mg GAE/100 g) and antioxidant capacity (from 6.74 to 7.98 μmol TE/g) in TC. Results suggest that tortilla chips added with huitlacoche can be an alternative to prepare this traditional edible fungus and produce healthier snacks, not fried and enriched with bioactive compounds.