Cereal bars functionalised with tempeh: nutritional composition,isoflavone content and consumer acceptance

The aim of this study was to produce cereal bars (CB) added with tempeh flour (TF) and evaluate the nutritional composition, fatty acids profile, isoflavone content and sensory acceptance. Tempeh was produced from organic soya beans cotyledons fermented by Rhizophus oligosporus followed by freeze-drying and milling in order to obtain the TF. The addition of 10%, 15% and 20% TF to CB resulted in both protein and lipid content increase and a higher polyunsaturated/saturated fatty acids ratio. The content of isoflavone aglycones, the forms considered to have higher biological activity, was higher in TF than in soya bean, which was also reflected in the CB chemical composition. An acceptance test showed that CB added with TF (up to 15%) were sensory accepted. Overall results suggest that the addition of TF as an ingredient in cereal bars allows improving the chemical and functional characteristics of this type of ready-to-eat foods.     

Hybrid films of polyimide containing in situ generated silver or palladium nanoparticles: Effect of the particle precursor and of the processing conditions on the morphology and the gas permeability

Hybrid organic/inorganic films have been prepared using different complexes soluble in a (BTDA/4,4′-ODA) poly(amic acid) solution. A silver based complex and two palladium based complexes were used and the metallic nanoparticles were formed by a single step process during the cure cycle applied to the film. Depending on the complex or the curing conditions used, either the nanoparticles formed were uniformly dispersed in the nanocomposite films, or the particles were also located at the film surface. The presence of the nanoparticles, whatever their composition, led to a decrease of the thermal degradation temperature in air atmosphere. The presence of 15 wt% of crystalline silver particles did not induce significant variation of the glass transition temperature and of the gas transport properties demonstrating low nanoparticle/matrix interactions. On the contrary, a pronounced effect in reducing the gas permeability for a wide variety of gases was observed for the nanocomposites containing the palladium based nanoparticles and this even for low palladium amount (5 wt%). Specific interactions between hydrogen and the Pd based nanoparticles were evidenced and the gas transport properties were discussed as a function of following parameters: the gas nature, the nanoparticle structure and composition, the developed morphology and the particle/matrix interactions.     

Potential application of microalga Spirulina platensis as a protein source

The high protein level of various microalgal species is one of the main reasons to consider them an unconventional source of this compound. Spirulina platensis stands out for being one of the richest protein sources of microbial origin (460–630 g kg^?1, dry matter basis), having similar protein levels when compared to meat and soybeans. The use of S. platensis in food can bring benefits to human health owing to its chemical composition, since it has high levels of vitamins, minerals, phenolics, essential fatty acids, amino acids and pigments. Furthermore, the development of new protein sources to supply the shortage of this nutrient is an urgent need, and protein from S. platensis plays an important role in this scenario. In this sense, extraction processes that allow maximum protein yield and total utilization of biomass is an urgent need, and ultrasonic waves have proven to be an effective extraction technique. The number of scientific papers related to protein fraction from S. platensis is still limited; thus further studies on its functional and technological properties are needed. © 2016 Society of Chemical Industry     

Physico‐chemical composition,fractionated glycerides and fatty acid profile of chicken skin fat

Skin is one of the several co‐products of chicken meat industries, considered as waste, being rarely utilized or underutilized. Brazil is the world leader in chicken exports (3.6 million tons) and the third largest producer with 10.9 million tons, from which 440 000 ton/year are residues. This work aimes at characterizing chicken skin fat (CSF), comparing it with soybean oil, a well‐known and abundant compound, evaluating the physico‐chemical composition, fractionated glycerides and fatty acid profile, searching for CSF use in interesterification reactions. For that, determination of peroxide and p‐anisidine values, as well as thiobarbituric acid, iodine, saponification, acidity, unsaponified matter and refraction indexes were accomplished, besides the glycerides fractionation, followed by FAME derivatization and identification by GC. The nutritional quality indexes were calculated from the lipid profile. CSF showed satisfactory quality due to low acidity (0.65 g oleic acid/100 g), peroxide (2.14 meq/kg), p‐anisidine (0.70 absorbance units/g) values, besides presenting high proportion of MUFA (40%). However, due to CSF low hypocholesterolemic/hypercholesterolemic value (HH = 2.72), it may be difficult to use it for nutritional purposes the way it is found, once it tends to increase cholesterol. CSF it is a promising residue for different purposes including interesterification reactions and biodiesel production.     

Occurrence of Salmonella spp. in persimmon fruit (Diospyrus kaki) and growth of Salmonella enteritidis on the peel and in the pulp of this fruit

The occurrence of Salmonella spp. on persimmon (Diospyrus kaki) surface of ‘Fuyu’ and ‘Rama Forte’ was evaluated during a 5-month-period (from April to August) of two season periods (years 2005 and 2006). The fruits were collected in wholesale (CEAGESP) and street markets in Sao Paulo and Campinas City, Brazil. A total of 582 fruits were analyzed using the BAX^® system, which is based on the Polymerase Chain Reaction (PCR). The ability of this pathogen to grow on the peel and pulp of the two persimmon varieties was also verified at different incubation periods at temperatures of 10, 20 and 30 °C. The growth parameters were obtained by modeling the experimental data using the Gompertz function. The presence of Salmonella spp. was evidenced in 5 of the 582 analyzed fruits (0.9% incidence). The growth studies showed that Salmonella enteritidis can grow on the peel as well as in the pulp of the two persimmon varieties studied incubated at 10, 20 and 30 °C and that low temperatures can reduce the generation rate but do not inhibit its growth.     

Original article: The effect of freezing at −18 °C and −70 °C with and without ascorbic acid on the stability of antioxidant in extracts of apple and orange fruits

The influence of low temperature and storage time on the antioxidant capacity of standard solutions and apple and orange extracts was evaluated. In addition, the effects of ascorbic acid (AA) addition to the fruit extracts in terms of antioxidant capacity, AA content and soluble and hydrolyzable polyphenol contents were also analysed. Polyphenol contents in both apple and orange extracts were stable during storage period, which reflected also in the antioxidant capacity stability. Freezing at ?18 °C did not result in different retention rates for polyphenols, AA and antioxidant capacity when compared to freezing at ?70 °C. However, vitamin C content in orange juice, without AA addition, slightly increased along the experimental period (10 days). Thus, this study shows that it may not be necessary to measure the antioxidant capacity immediately after the preparation of fruit extracts or antioxidant standard solutions.