High protein and vitamin cereal bars: enzymatic and vitamins C and E stability during storage

Cereal-based products have become an excellent vehicle for delivering tasty functional food ingredients to busy consumers. One emerging trends is food products formulates with soy protein because of its proven health benefits. Because of the potential usefulness of these products, it was considered of interest to determine the stability of cereal bars based on soy protein, wheat germ and oat, enriched with vitamin C (ascorbic acid) and E (acetate of a-tocopherol 50%), during the storage. Three films with different properties of barrier (A: PET/PEBD; B: PETMET/PEBD; C: PET/PEBD/ALIPEBD) were used as packing and the cereal bars were stored at temperature (25 +/- 2 degrees C) and relative humidity ambient (56%) for six months. The stability of vitamin C, vitamin E and, its lipase and peroxidase activity was verified. During the study, the cereal bars packed in three tested films presented retention in the vitamin C lesser that 50%. However, packing structuralized with aluminum (C) leaf provided to minor speed of reaction during the storage, k = 0.00437 (-day), and greater time of half-life (146 days). The vitamin E (acetate of a-tocopherol) in the cereal bars presented a little variation during the storage. It had a significant (p < or = 0.05) increase in the peroxidase activity at 90 days of storage in the packages tested, while that the lipase activity demonstrated no significant increase during the period studied.     

Storage of cereal bars with mesquite cotyledon (Prosopis chilensis (Mol) Stuntz)

The use of walnut or peanut in the elaboration of cereal bars represents a possible risk of undesirable changes during their storage due to their high content of unsaturated fatty acids in the oil; oxidizing of the fatty acids is one of the main causes of deterioration. Development of new snack products implies the use of packages that should protect the food against the damage caused by light and reduce the oxygen concentration of in their interior. The objective of this investigation was to evaluate the physical, chemical and sensory changes in the storage of cereal bars with peanut or walnut and mezquite cotyledon subjected to two thermal treatments, packed in cellophane or milky polypropilene. Four types of bars were elaborated with 6% of mezquite cotyledon, treated by microwaves or toasted, and with 18% of peanut or walnut. The bars were stored for 90 days at room temperature; and each 30 days it was measured moisture content, peroxides index, water activity, sensory quality and acceptability. The peroxides values (4.9-13.8 meq/kg of oil) indicates that the shelf life of the bars in all the studied treatments was 90 days. The packaging materials used allows to maintain in good conditions, for 3 months, the cereals bars of moisture (7.4-11.2%), water activity (0.50-0.65) and sensory acceptability.     

Development of a food of intermediate moistness from extracts of corn and soybean

Precooked cereal:oilseed blends have potential use as intermediate moisture food supplements. On this basis, some formulations from corn:soy extrudates, and other ingredients, were prepared and evaluated. The main objective of this work was to develop a prototype intermediate moisture vegetable food, stable at room temperature, of low cost, and inexpensive packaging requirements. The technological process involves thermal and enzymatic modification of corn and soy blends. The final product can be suspended in water and consumed as a high energy-protein beverage. Its proximate composition is similar to that of sweetened condensed milk.     

Preparation and characterization of soy protein isolate–carboxymethylated konjac glucomannan blend films

To improve the mechanical and water vapor barrier properties of soy protein films, the transparent films were prepared by blending 5 wt % soy protein isolate (SPI) alkaline water solution with 2 wt % carboxymethylated konjac glucomannan (CMKGM) aqueous solution and drying at 30 °C. The structure and properties of the blend films were studied by infrared spectroscopy, wide‐angle X‐ray diffraction spectroscopy, scanning electron microscopy, thermogravimetric analysis, differential thermal analysis, and measurements of mechanical properties and water vapor transmission. The results demonstrated a strong interaction and good miscibility between SPI and CMKGM due to intermolecular hydrogen bonding. The thermostability and mechanical and water vapor barrier properties of blend films were greatly enhanced due to the strong intermolecular hydrogen bonding between SPI and CMKGM. The tensile strength and breaking elongation of blend films increased with the increase of CMKGM content: the maximum values achieved were 54.6 MPa and 37%, respectively, when the CMKGM content was 70 wt %. The water vapor transmission of blend films decreased with the increase of CMKGM content: the lowest value achieved was 74.8 mg · cm^?2 · d^?1 when the CMKGM content was 70 wt %. The SPI–CMKGM blend films provide promising applications to fresh food packaging. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1095–1099, 2003     

Tensile and dynamic mechanical properties of improved ultrathin polymeric films

Tensile and dynamic mechanical properties of improved ultrathin polymeric films for magnetic tapes are presented. These films include poly(ethylene terephthalate) or PET, poly(ethylene naphthalate) or PEN, and aromatic polyamide (ARAMID). PET film is currently the standard substrate used for magnetic tapes; thinner tensilized‐type PET, PEN, and ARAMID were recently used as alternate substrates with improved material properties. The thickness of the films ranges from 6.2 to 4.8 μm. Young's modulus of elasticity, F5 value, strain‐at‐yield, breaking strength, and strain‐at‐break were obtained at low strain rates by using a tensile machine. Storage (or elastic) modulus, E′, and the loss tangent, tan δ, which is a measurement of viscous energy dissipation, are measured by using a dynamic mechanical analyzer at temperature ranges of ?50 to 150°C (for PET), and ?50 to 210°C (for PEN and ARAMID), and at a frequency range of 0.016 to 29 Hz. Frequency–temperature superposition was used to predict the dynamic mechanical behavior of the films over a 28 decade frequency range. Results show that ARAMID and tensilized films tend to have higher strength and moduli than standard PET and PEN. The rates of decrease of storage modulus as a function of temperature are lower for PET films than those for PEN and ARAMID films. Storage modulus for PEN films are higher than that for PET films at high frequencies, but this relationship reverses at low frequencies. ARAMID has the highest modulus and strength among the films in this study. The relationship between polymeric structure and mechanical properties are also discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2225–2244, 2002     

分子筛改性PET纤维的制备和性能研究

将分子筛、添加剂(分散剂、交联剂)以不同的比例和PET切片共混进行母粒法熔融纺丝,制得分子筛改性PET纤维,并测定纤维的力学性能、吸湿性能和染色性能。结果表明：当纤维中分子筛质量分数为2%时,改性PET纤维的可纺性较好;添加剂含量存在最佳值,与纯PET纤维相比,分子筛：分散剂(质量比)为1．0：1．8时,改性纤维断裂强度提高39．7%,含湿率提高30．4%,上染率提高7．7%;分子筛：分散剂：交联剂(质量比)为1．0：1．2：0．2时,改性纤维断裂强度可提高62．7%。分子筛在改性PET纤维中分散均匀,并形成了拟网状结构。     

PTT/PA6拉伸丝的形态与性能的研究

考察了聚对苯二甲酸丙二醇酯/聚酰胺6(PTT/PA6)拉伸丝的形态,测试了其线密度、断裂强度、回潮率、热收缩率及卷曲性能,并与聚对苯二甲酸乙二醇酯/聚酰胺6(PET/PA6)拉伸丝进行了对比.结果表明:PTT/PA6拉伸丝横截面为橘瓣型,裂离后为三角形.PTT/PA6拉伸丝的断裂强度、断裂功和卷曲收缩率随纺丝速度的增加...     

Linking morphology changes to barrier properties of polymeric packaging for microwave‐assisted thermal sterilized food

It is a priority to develop polymeric packaging that can withstand microwave‐assisted thermal sterilization (MATS) and maintain the quality of low‐acid foods during long‐term storage. In this study, we explored changes in the morphology of pouch films with two multi‐layer structures. The films are based on barrier layers of metal oxide‐coated poly(ethylene terephthalate) (PET) (film A) and ethylene vinyl alcohol (EVOH) (film B). A 8‐oz model food in pouches was processed with MATS (F₀ = 9.0 min) and stored at 23, 35 and 45 °C for up to 12 months. Findings reveal that the oxygen barrier of film A was influenced by the coating and crystallinity of PET. The oxygen barrier of film B was primarily affected by the moisture content of the EVOH polymer. Results also show that changes in barrier properties depended on storage temperature. Recrystallization in polymer might be an important morphological change that occurs during storages. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45481.     

Development of a melt‐extrudable biobased soy flour/polyethylene blend for multilayer film applications

Monolayer and multilayer films from biobased linear low‐density polyethylene and milled soy flour were produced through cast film coextrusion processes using conventional thermoplastic processing equipment. Films containing 10 and 20% by weight of soy flour milled to maximum particle sizes of 8, 11, and 22 µm were extruded and characterized as a packaging film material. Water resistance, tensile properties, and gas permeability were measured on each film and analyzed with respects to the soy particle size, soy loading, and layer configuration in the multilayer film structure. Mechanical properties results indicated that ultimate elongation of the soy‐containing films decreased by as much as 14% compared to the control, while tensile strength and maximum load testing did not reveal any identifiable trends. Monolayer soy‐containing film showed high moisture sensitivity, as measured by contact angle and absorption testing, while the multilayer films demonstrated a more hydrophobic nature as indicated by higher contact angle measurements. This increase in hydrophobic properties is due to protective polyolefin skin layers, which are more hydrophobic. Oxygen transmission rates of the multilayer films decreased by 38% due to the presence of soy flour as compared to the control that did not contain any soy flour. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40707.     

Bacterial nanocellulose‐reinforced arabinoxylan films

There is an increasing interest in substituting today's films for food packaging applications with films based on renewable resources. For this purpose, rye arabinoxylans, unmodified and enzymatically debranched, were studied for the preparation of neat films and composite films reinforced with bacterial cellulose (BC). Mixing in a homogenizer produced optically transparent, uniform films. Physical and mechanical characteristics of such films are here reported. Debranching of the arabinoxylan caused an increase in its crystallinity of 20%. Debranching as well as reinforcement with BC resulted in a decrease of the moisture sorption of the films. The debranching also resulted in a reduced breaking strain while the reinforcement with BC increased stiffness and strength of the films. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

聚烯烃液体包装专用料的研制

采用优选法试验制得的聚烯烃液体包装专用料,是由LDPE、HDPE、LLDPE、NPA型加工助剂共混配制成的高强度液体包装专用料。经吹塑制成液体包装膜后,可用于牛奶等液体的包装,具有破损率低、实际应用好等特点。这种液体包装专用料也可以代替LDPE重包装料制成重包装袋,用于包装各类材料。     

1 100 dtex涤纶帘子线直捻机加捻工艺探讨

采用1 100 dtex涤纶工业丝,在K3501型直捻机上加捻生产涤纶帘子线,锭速8 000 r／min,捻度 440 T／m,外纱张力65％,超喂比5％,防叠角(20±1)°,生产的复捻线断裂强力大于145 N,断裂强力及断裂伸长不匀率均小于1％。同两步法加捻相比,产晶质量和经济效益均明显提高。     

Biomimetic soy protein-based exterior-use films with excellent UV-blocking performance from catechol derivative Acacia mangium tannin

Polymer plastic is the main component of current outdoor packaging film materials that are mostly derived from fossil fuels. Its poor ultraviolet (UV) barrier performance and short service life caused by aging degradation result in increased non-renewable consumption and environmental pollution. The most effective way to solve these problems is the development of a biomass-based and eco-friendly packaging with excellent UV-blocking performance. Herein, inspired by mussels, a facile strategy is reported for the preparation of a biomimetic polymeric material via the incorporation of a biomass-derived catechol derivative Acacia mangium tannin (AMT) into a biodegradable soy protein isolate (SPI) matrix. The morphologies, mechanical, thermal properties, and UV-blocking abilities and mechanisms of the modified films were evaluated. With the increase of the AMT content, the stress of the composite film was found to gradually increase, and the modified SPI composite film exhibited a powerful tensile strength of 7.64 MPa and a high breaking strain of 145.6%. After the introduction of AMT, the films exhibited excellent UV-blocking performance. As both SPI and AMT are biodegradable, this work presents an innovative design strategy for fully-biodegradable and robust polymeric materials with excellent UV-blocking performance that have promising potential applications in packaging.     

Adhesion of UV-Cured Laminates of Poly(ethylene-2,6-naphthalate) (PEN) and Poly(ethylene terephthalate) (PET) films

This paper describes the properties of an ultraviolet (UV) curable laminating adhesive system that can be used with PEN, PET and UV-stabilized PET films. The adhesive system that contains (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (TPO) as photoinitiator was optimally cured with a V-bulb fitted ultraviolet irradiator. The laminated structures built with this adhesive system and PEN, PET and UV-stabilized PET films showed a large manufacturing operating window, both in terms of adhesive layer thickness, initial peel strengths above 1500 N/m, V- and D-bulb UV sources and curing speeds from 5– 10 m/min. The 600-h dry heat aging tests indicated that the UV-stabilized PET films underwent less than approximately 1% decrease in light transmission and less than a 1% gain in color. The UV-stabilized PET film and its laminate showed particularly strong retention of optical properties under damp aging and QUV weathering, compared to PEN and non-UV-stabilized PET films. Finally, the peel strengths of the laminates were retained to greater than 1300 N/m for laminate structures of 50 μm film thickness, whereas structures made from thicker films retained approx. 40–60% (700–1100 N/m) of their initial peel strength.     

Mechanical,hygroscopic, and thermal properties of ultrathin polymeric substrates for magnetic tapes

Mechanical, hygroscopic, and thermal properties of improved ultrathin polymeric films for magnetic tapes are presented. These films include poly(ethylene terephthalate) (PET), poly(ethylene naphthalate) (PEN), and aromatic polyamide (ARAMID). PET films are currently the most commonly used polymeric substrate material for magnetic tapes, followed by PEN and ARAMID. The thickness of the films ranges from 6.2 to 4.8 μm. Tensile tests were run to obtain the Young's modulus, F5 value, strain at yield, breaking strength, and strain at break. The storage modulus, E′, and the loss tangent, tan δ, were measured using a dynamic mechanical analyzer (DMA) at temperature ranges of ?50 to 150°C (for PET) and ?50 to 210°C (for PEN and ARAMID) and at a frequency range of 0.016–28 Hz. Frequency–temperature superposition was used to predict the dynamic mechanical behavior of the films over a 28‐decade frequency range. Short‐term longitudinal creep behavior of the films during 10, 30, 60, and 300 s, 7 MPa, were measured at 25 and 55°C. Long‐term longitudinal creep measurements were performed at 25, 40, and 55°C for 100 h. The Poisson's ratio and 50‐h long‐term lateral creep were measured at 25°C/15% RH, 25°C/50% RH, 25°C/80% RH, and 40°C/50% RH. The in‐plane coefficient of hygroscopic expansion (CHE) at 25°C/20–80% RH and the coefficient of thermal expansion (CTE) at 30–70°C were measured for all the samples. The properties for all films are summarized. The relationship between the polymeric structure and the mechanical and physical properties are discussed, based on the molecular structure, crystallinity, and molecular orientation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3052–3080, 2003     

Recycling of multilayer packaging using a reversible cross-linking adhesive

Plastic-based multilayer packaging has an important function on the packaging market, but is currently not recyclable as the polymer layers used are usually thermodynamically immiscible. This work therefore follows the approach to prepare separable multilayer packaging using a packaging adhesive modified with thermally unstable adducts, and proposes a corresponding recycling process. For this purpose, typical multilayer structures (polyethylene (PE)// polyethylene terephtalate (PET), PET//aluminum, and PE//aluminum) were prepared by curing furan-/maleimide-functionalized polyurethane (PU)-prepolymers with a three-functional cross-linking agent. Adhesions of up to over 3N per 15 mm test specimen were measured or substrate failures of PET films were observed. However, heating in dimethylsulfoxide, the retro-Diels–Alder reaction takes place and the cross-linked adhesive turns thermoplastic and dissolves in the solvent. Thus, the laminate separates and the pure PE, PET, and aluminum foils can be recovered without any PU residue.     

A comparative study of the interaction between the dried ink layer and PLA film used for packaging purposes

This research aims at comparing the interactions between the water-based printing ink and polylactide (PLA) printing base. As a reference base, a polyethylene terephthalate (PET) film was chosen. The wettability of both films was investigated. The Owens–Wendt method was applied to calculate the surface free energy (SFE). The values of SFE and its polar and dispersive components were compared with the surface tension (ST) of the ink and the polar and dispersive components of ST. The wetting envelopes of the investigated PLA and PET films are presented. Finally, the bonding strength between the dried ink layer and the printing base was analyzed. The PET film exhibited higher values of SFE. However, the bonding strength between the dried ink layer and the printing base was higher for PLA films. Our results reveal that PLA films can be an excellent choice as packaging materials, with comparable or even better print quality than conventional fossil-based plastics.     

Amaranth bars enriched with fructans: acceptability and nutritional value

There is an increasing appeal for convenience foods with potential health benefits to the consumer. Raw materials with high nutritional value and functional properties must be used on the development of these food products. Amaranth is a gluten-free grain with high nutrition value. Inulin and oligofructose are prebiotic ingredients presenting effects as the enhancement of calcium absorption. Amaranth bars enriched with inulin and oligofructose were developed in the flavors: banana, Brazilian nuts and dried grape, coconut, peach, strawberry and wall nut. The proximate composition were determined and compared to commercial cereal bars, available in traditional (n=59), light (n=60), diet (n=8), with soy (n=10) and quinoa (n=1) categories. Amaranth bars present mean global acceptance values from 6.3 to 7.6 on a 9-point hedonic scale, nutritional advantages as compared to commercial cereal bars (caloric reduction and higher levels of dietary fiber). Although amaranth is an unknown raw material in Brazil, it shows good potential to be used in the manufacturing of ready-to-eat products. As they are gluten free, these amaranth bars are also an alternative product for celiacs, also contributing to the enhancement of calcium absorption, a problem frequently observed in these patients.     

吸湿阻燃涤纶短纤维的开发

以对苯二甲酸乙二酯为主体分子结构,添加共聚型磷系阻燃剂和含有吸湿官能团的单体改性聚酯大分子链,以其改性聚酯切片为原料制得吸湿阻燃短纤维,其断裂强度、断裂伸长率等主要指标达到要求;制得阻燃涤纶织物极限氧指数大于30%。     

Optimization of Process Parameters for Spray Drying of Fermented Soy Milk

Generally used as an inexpensive source of high-quality protein with many other health-promoting properties, soy milk offers an interesting alternative when fermented. Fermentation with lactic acid bacteria brings about the value addition to soy milk, making a nutritious probiotic food product. Dehydration helps to achieve longer shelf life and easier transportation and storage, enabling wider distribution of the product. The present work pertains to optimization of process parameters for spray drying of fermented soy milk using response surface methodology (RSM). The process parameters studied include inlet air temperature, aspirator speed (air flow rate), feed flow rate, and atomization pressure. The experiments were designed using the central composite design tool. Residual moisture content was found to be low at higher inlet air temperature, lower feed flow rate, higher atomization pressure, and higher air flow rate. Porosity reduced with increased atomization pressure. Higher product yield was obtained at high air flow rate and low feed flow rate. The increase in the atomization pressure increases the cohesiveness between particles, resulting in reduced flowability. An increase in the inlet air temperature greatly reduces the viability and the isoflavone aglycone content in the product. Protein denaturation during the process was found to reduce the product solubility.