RESUMO

The aim of the present work was to fortify yogurt by adding a stripped weakfish (Cynoscion guatucupa) protein hydrolysate obtained with the enzyme Protamex and microencapsulated by spray drying, using maltodextrin (MD) as wall material. The effects on the physicochemical properties, syneresis, texture, viscoelasticity, antioxidant and ACE inhibitory activities of yogurt after 1 and 7 days of storage were evaluated. In addition, microbiological and sensory analyses were performed. Four yogurt formulations were prepared: control yogurt (without additives, YC), yogurt with MD (2.1%, YMD), with the free hydrolysate (1.4%, YH) and the microencapsulated hydrolysate (3.5%, YHEn). Yogurts to which free and microencapsulated hydrolysates were added presented similar characteristics, such as a slight reduction in pH and increased acidity, with a greater tendency to present a yellow color compared with the control yogurt. Moreover, they showed less syneresis, the lowest value being that of YHEn, which also showed a slight increase in cohesiveness and greater rheological stability after one week of storage. All yogurts showed high counts of the microorganisms used as starters. The hydrolysate presence in both forms resulted in yogurts with antioxidant activity and potent ACE-inhibitory activity, which were maintained after 7 days of storage. The incorporation of the hydrolysate in the microencapsulated form presented greater advantages than the direct incorporation, since encapsulation masked the fishy flavor of the hydrolysate, resulting in stable and sensorily acceptable yogurts with antioxidant and ACE inhibitory activities.

RESUMO

In this study, edible packaging based on discarded green banana (Musa acuminata AAA) flour (whole banana and banana peel flours) was developed for food applications. Films were characterized in terms of film-forming ability, mechanical, barrier, thermal, microbiological, and sensory properties. The film forming solutions were studied for rheological properties. Two formulations were selected based on their film-forming ability: whole banana flour (2.5%), peel flour (1.5%) and glycerol (1.0 %, F-1.0 G or 1.5%, F-1.5 G). Adding 1.5% plasticizer, due to the hygroscopic effect, favored the water retention of the films, increasing the density, which also resulted in a decrease in lightness and transparency. Water activity shows no difference between the two formulations, which were water resistant for at least 25 h. DSC results showed a similar melting temperature (Tm) for both films, around 122 °C. Both films solutions showed a viscoelastic behavior in the frequency spectrum, being the elastic modulus greater in F-1.0 G film than F-1.5 G film at low frequency. F-1.0 G film was less firm, deformable and elastic, with a less compact structure and a rougher surface as confirmed by AFM, favoring a higher water vapor permeability with respect to F.1.5 G film. Microorganisms such as Enterobacteria and Staphylococcus aureus were not found in the films after a period of storage (1 year under ambient conditions). The F-1.0 G film with added spices (cumin, oregano, garlic, onion, pepper, and nutmeg) was tested for some food applications: as a snack (with or without heat treatment) and as a wrap for grilled chicken. The performance of the seasoned film during chilled storage of chicken breast was also studied. Sensory evaluation showed good overall acceptability of all applications. In addition, the chicken breast wrapped with the seasoned film registered lower counts (1-log cycle) than the control (covered with a polystyrene bag) and the film without spices. Green banana flour is a promising material to develop edible films for food applications.

RESUMO

The purpose of this work was to obtain chorizos by partially fat replacing with banana flour (whole or peeled). These chorizos were formulated with 3% pork fat and 24% whole banana flour (BC) or banana peel flour (BPC). A third formulation of chorizo with 15% pork fat and 12% wheat flour (WC) was also produced for comparison. Cooking loss was 12.5% for the WC, while for the BC and BPC chorizos it was 7.2% and 6.9%, respectively. All three products had similar water, protein, and ash contents, whereas carbohydrate and fiber contents were the main changes in composition. The color of the three different formulations did not change markedly, but an increase in yellowness and chromaticity was observed in the BC chorizo, as well as a slight decrease in lightness and in the whiteness index in the BPC one. Textural properties declined from day 0; from day 3 onwards, they remained constant in all chorizos and properties, except for BC lot in cohesiveness. Mesophilic aerobic bacteria, as well as mold and yeast counts, were predominantly high in the WC during chilled storage. Moreover, the sensory analysis indicated high acceptability of the formulated with wheat or whole banana flour, although those with banana peel flour scored slightly lower. This study shows that incorporating banana flours into the formulation successfully reduced the incorporation of pork back-fat, resulting in excellent quality sensorial characteristics due to the technological parameters and sensory acceptance.

RESUMO

This study aimed to develop a fiber-enriched Frankfurter-type sausage by incorporating underutilized green banana flours as a meat extender, replacing wheat flour with banana flours (8%). A low-fat formulation substituting 12% pork fat with 24% banana peel flour was also studied. Sausages were stored at 4 °C/15 days. Cooking loss was low (5.6-4.1%) in all formulations and the substitution of wheat flour with banana flour did not modify moisture and protein composition, while carbohydrate, fiber, and ashes varied with the flour composition. In the low-fat sausages, fiber carbohydrate and ashes increased the most. Texture and color parameters were very similar for high-fat sausages throughout storage, although low-fat sausage showed higher hardness, while chewiness, L*, and whiteness tended to decrease. During the first week of storage, the microbial growth was scarce and then, an increase, except in the low-fat batch, in which growth remained constant. Enterobacteria and Staphylococcus aureus were not detected during storage. Sensory attributes throughout storage were very similar for all high-fat sausages; the odor in the formulations was defined as "different" but not unpleasant. The low-fat sausages, defined as a new product different from conventional sausages, were well accepted by the panelist. Banana flours are a suitable ingredient option to add nutritional value to Frankfurter-type sausages, which can be consumed by the wheat allergic population.

RESUMO

The interactions between liposomes and fish myofibrillar protein (surimi ground salted protein, SURP) were evaluated. Liposomes prepared with ultrapure phosphatidylcholine (UPC) or partially purified phosphatidylcholine (PPC) were dispersed at different weight ratio on SURP. Changes in protein stability and structure were evaluated using FTIR, intrinsic fluorescence and free sulfhydryl groups, and changes in liposome properties were studied by dynamic light scattering and electron microscopy. PPC promoted denaturation and aggregation of SURP, reflected in secondary structure loss, exposure of tyrosine residues and increment of free sulfhydryl. UPC produced partial unfolding and changes in the secondary structure of SURP from α-helical to ß-strand. Liposome size increased by about 40% and showed modified surface charge after SURP exposure, indicating the formation of protein corona. Surface charge and composition of liposomes influence SURP stability and could exert different effects on the myofibrillar protein network, which is important for liposome applications in surimi products.

Assuntos

RESUMO

This manuscript evaluates the potential application of active nanocomposite films based on soy protein isolate (SPI)-montmorillonite (MMT)-clove essential oil (CEO) to the preservation of muscle fillets of bluefin tuna (Thunnus thynnus) during refrigerated storage, and furthermore analyzes whether the clay diffuses from the package to food. SPI films with: CEO (SPI-CEO), MMT (SPI-MMT), or both CEO and MMT (SPI-MMT-CEO), were prepared and used to cover tuna fillets during 17days of storage at 2°C. Polyethylene films were also used as control. Protein films nanoreinforced with 10g MMT/100g SPI and activated with CEO were able to decrease microbial growth (evaluated by TVBN and microorganism counts) and lipid autooxidation (evaluated according to the TBA index, FTIR and color parameters) of tuna fillets during the storage period studied. The presence of clay seemed to favor the release of the active principles of clove oil by prolonging its antimicrobial (especially effective to inhibit Pseudomonas spp.) and antioxidant activity over time without observing the diffusion of the clay's own metals (Si and Al) from the nanocomposite materials to the muscle of fish. These results are encouraging for the use of nanocomposite films in food packaging.

Assuntos