Stable retorted whey protein beverages with 5% protein concentration were prepared. The effect of protein concentration, fat concentration and homogenization pressure on the heat stability and the stability of emulsions of sterilized whey protein beverages was determined. Beverages containing >1% protein formed aggregates during the heat treatment. Food grade additives were added to the beverages with >1% protein to determine if the heat stability could be improved. Lecithins and polyphosphates improved the heat stability while hydrocolloids decreased the heat stability. Lecithins improved the heat stability of emulsions better than polyphosphates but polyphosphates were more effective in beverages without fat. Lecithins modified by acetylation or hydrolysis provided more protection against heat denaturation of proteins than regular lecithin. Acetylated lecithin created the emulsions most stable against creaming. Improvement in the emulsion stability by the use of phospholipids was associated with a more negative charge at the interface of the fat droplets. The effect of polyphosphates on the heat stability was related to the chain length of the polyphosphates. Short chain polyphosphates (dp~4) were more effective than other polyphosphates. Polyphosphates probably improved the heat stability of the systems by changing the structure of water and this prevented aggregation of whey proteins. Hydrocolloids decreased heat stability most probably through thermodynamic incompatibility that locally increased the concentration of proteins and promoted aggregation during the heat treatment.The effect of homogenization pressure, concentration of acetylated lecithin, and the concentration of short chain polyphosphate on the storage stability of retorted whey protein beverages containing 5% protein and 3% fat was determined. The creaming index and particle size index changed over 28 d of storage and indicated creaming of the emulsions. The use of homogenization pressures of 55 and 90 MPa compared to 20 MPa reduced the magnitude of the change of the particle size index and creaming index during storage. Inclusion of polyphosphates reduced the storage stability of the emulsions. Optimization of parameters showed that emulsions formulated with 5% protein, 3% fat and 0.3% lecithin without polyphosphates and homogenized at 90 MPa had the best stability after 28 d of storage.

Master of Science / Department of Grain Science and Industry / Greg Aldrich / Since 2010, there have been seven recalls related to thiamine deficiency in cat food products (FDA, 2017; FSA, 2017). Cats have a high requirement of thiamine (5.6 mg/kg), and deficiencies can lead to death within a month if not treated (AAFCO, 2017). A few studies have been published regarding the impact of retort processing on thiamine loss in canned pet food but no work has been reported on heat penetration in other containers (pouches and trays). Therefore, our objectives were to determine the effect of container size and type on thiamine retention during processing of cat food. Our hypothesis was that thiamine retention would be impacted by container size and type. To address this, a 2x3 factorial arrangement of treatments in which two container sizes (small: 89-104 mL vs medium: 163-207 mL) and three container types (can, pouch, and tray) were evaluated for B-vitamin losses and thermal process lethality of a wet pet food. A model wet cat loaf type formula was produced for all six experimental treatments and each was processed in duplicate over six-days. All ingredients including the vitamin premix (10x level) were thoroughly mixed, heated to 43ºC, and containers were manually filled. The filled and sealed containers were cooked in a retort (cans: SJ Reid Retort, Bellingham, WA; trays and pouches: FMC retort, Madera, CA) with thermocouples attached to the center of representative containers (n=14) in each batch. Software (Calsoft Systems, v. 5.0.5) was used to record the internal temperatures. The retort time was targeted to meet an F₀=8 at 121ºC and 21 PSI. Treatment sample were analyzed for included pH, moisture, crude protein, crude fat, ash, and B-vitamins. Results were analyzed using the GLM procedure in SAS (v. 9.4; Cary, NC) with means and interactions separated using Fisher LSD method by significant F and an α of 5%. The proximate composition and pH were similar (P > 0.10) among treatments. There was an interaction (P < 0.05) between container size and type for time to reach the F₀=8; wherein, the medium can and tray had the longest time (45.5 and 46.3 min, respectively); the small can and tray, and medium pouch were intermediate (35.4, 36.0, and 32.0 min, respectively); and the small pouch had the shortest time (36.0 min). There was no difference for either main effect of container type or size on heating lethality values (each main effect average F₀=10.3) and total lethality ranged from 12.7-16.7 min. Thiamine retention was lowest (70%) among the B-vitamins, and there was minimal loss throughout the process. The excess heating beyond F₀=8 may account for the dramatic impact on the retention of heat labile nutrients like thiamine. This may be more difficult to control in the newer packaging systems like pouches and trays.

The performance of a new horizontal retort (Steriflow Standard 1-Basket Model, Barriquand, Paris, France) was evaluated on the basis of temperature, heat and lethality distribution. Time-temperature data for these studies were obtained from bare thermocouples (type T), and rectangular bricks fabricated from Teflon$ sp{ rm TM}$ and Lexan$ sp{ rm TM}$ with thermocouples positioned at their geometrical centres. / The effect of entrapped air on processing parameters for bricks packaged in retort pouches was determined using silicone rubber bricks (10 x 14.5 x 2 cm), containing 5 thermocouples with their junctions positioned from the geometrical centre to near the top surface. The processing media employed were steam/air at two temperatures (121.1$ sp circ$C and 115.6$ sp circ$C) and two levels of superimposed air over-pressure, corresponding to 65% and 75% steam content. / With the exception of the highest level of over-pressure (116 kPa), 60 ml of entrapped air caused the heating rate index (f$ sb{ rm h}$) to double. At low levels of air over-pressures, the slowest heating region (often assumed to be the geometrical centre) in the brick was shifted to a height equivalent to 3/4 of the brick thickness from the centre when the entrapped air volume was 60 ml. For similar conditions, the location receiving the least combined lethality during heating and cooling was near the top surface of the brick.

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Made available in DSpace on 2014-06-11T19:31:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-12-17Bitstream added on 2014-06-13T20:42:04Z : No. of bitstreams: 1 gumerato_hf_dr_botfca.pdf: 735190 bytes, checksum: f1454b535f3ff650b6cf9e96b355f222 (MD5) / Universidade Estadual Paulista (UNESP) / Foi estudado processo de transferência de calor transiente por agitação intermitente em embalagens, visando a conservação de alimentos por tratamento térmico com processo mais econômico e que mantivesse a qualidade de alimentícios. Objetivou-se o desenvolvimento de um processo baseado em agitação intermitente de embalagens para aplicação em pasteurização ou esterilização. O estudo da transferência de calor transiente em sistema com movimento linear alternado foi realizado em embalagens metálicas, em 4 meios simulantes de diferentes viscosidades e massas específicas: 3 óleos orgânicos e água. Foram combinados efeitos de 5 tratamentos, sendo: meio simulante (4 níveis), espaços livres (3 níveis), freqüência de agitação (4 níveis), amplitude de agitação (2 níveis) e posições das latas (4 níveis). Os ensaios de aquecimento e resfriamento foram feitos em tanque com água a temperatura de 98°C e 17 a 20°C, respectivamente. Com os dados de penetração de calor em cada experimento foram calculados os parâmetros de penetração de calor fh, jh, fc e jc. Os resultados foram modelados utilizando-se grupos de números adimensionais e foram expressos em Nusselt, Prandtl, Reynolds e... / Transient heat transfer was studied by intermittent shake in cans with linear system, in order to preserve food by heat thermally processed, applying process more economic, and keeping high food quality. The objective was developing a process based on intermittent shake in cans to applying in pasteurisation or sterilisation process. Heat transfer was carried out in metallic cans filled four different simulate medium: water, Neutral oil 150 and 500 and Bright stock oil. It was arranged five treatments: simulate media (4 levels), head space (3 levels), agitation frequency (4 levels), length of agitation (2 levels) and cans positions (4 levels). The tests were carried out in hot water tank at temperature 98°C and cool at 17~20°C. Heat transfer parameters (fh, jh, fc and jc) for each test was calculated. Results were expressed applying dimensionless numbers equations for heat and cool. Data were computed pplying dimensionless numbers and were assign as Nusselt, Prandtl, Reynolds and trigonometric functions. Results obtained from linear shake system were compared with end-over-end agitation, and shake linear system showed more efficient. Shake linear system can be applied in pasteurisation or static retorts with simple internal structure fits...(Complete abstract, click electronic access below)

Resumo: Foi estudado processo de transferência de calor transiente por agitação intermitente em embalagens, visando a conservação de alimentos por tratamento térmico com processo mais econômico e que mantivesse a qualidade de alimentícios. Objetivou-se o desenvolvimento de um processo baseado em agitação intermitente de embalagens para aplicação em pasteurização ou esterilização. O estudo da transferência de calor transiente em sistema com movimento linear alternado foi realizado em embalagens metálicas, em 4 meios simulantes de diferentes viscosidades e massas específicas: 3 óleos orgânicos e água. Foram combinados efeitos de 5 tratamentos, sendo: meio simulante (4 níveis), espaços livres (3 níveis), freqüência de agitação (4 níveis), amplitude de agitação (2 níveis) e posições das latas (4 níveis). Os ensaios de aquecimento e resfriamento foram feitos em tanque com água a temperatura de 98°C e 17 a 20°C, respectivamente. Com os dados de penetração de calor em cada experimento foram calculados os parâmetros de penetração de calor fh, jh, fc e jc. Os resultados foram modelados utilizando-se grupos de números adimensionais e foram expressos em Nusselt, Prandtl, Reynolds e...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Transient heat transfer was studied by intermittent shake in cans with linear system, in order to preserve food by heat thermally processed, applying process more economic, and keeping high food quality. The objective was developing a process based on intermittent shake in cans to applying in pasteurisation or sterilisation process. Heat transfer was carried out in metallic cans filled four different simulate medium: water, Neutral oil 150 and 500 and Bright stock oil. It was arranged five treatments: simulate media (4 levels), head space (3 levels), agitation frequency (4 levels), length of agitation (2 levels) and cans positions (4 levels). The tests were carried out in hot water tank at temperature 98°C and cool at 17~20°C. Heat transfer parameters (fh, jh, fc and jc) for each test was calculated. Results were expressed applying dimensionless numbers equations for heat and cool. Data were computed pplying dimensionless numbers and were assign as Nusselt, Prandtl, Reynolds and trigonometric functions. Results obtained from linear shake system were compared with end-over-end agitation, and shake linear system showed more efficient. Shake linear system can be applied in pasteurisation or static retorts with simple internal structure fits...(Complete abstract, click electronic access below) / Orientador: José Santo Goldoni / Coorientador: Flávio Luís Schmidt / Banca: Jayme de Toledo Piza e Almeida Neto / Banca: Marco Antonio M. Biaggioni / Banca: Alfredo de Almeida Vitali / Banca: Flávio Luis Schimidt / Doutor

Orientadores: Carlos Alberto Rodrigues Anjos, Marcelo Cristianini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-09T22:28:35Z (GMT). No. of bitstreams: 1 RojaJunior_NelsonPedro_M.pdf: 1008534 bytes, checksum: f8af7df8acbf3611069d44225ab3d001 (MD5) Previous issue date: 2008 / Resumo: As rações operacionais s~so meios fundamentais para a execução das atividades de treinamento e desdobramento real das Forcas Armadas do mundo inteiro, sendo empregadas ainda em circunstancias de contingencia de ordem civil. Neste sentido, a Força Aerea Brasileira, na busca continuada de solucoes e melhorias na area do fornecimento de alimentos, vem priorizando pesquisas para o desenvolvimento de produtos de pronto consumo. Nessa linha, o objetivo principal desta investigacao foi desenvolver uma refeicao de pronto consumo em embalagens flexiveis esterilizaveis, para equipagens de aeronaves e para uso terrestre, em substituicao ao sistema atualmente utilizado pelas Forças Armadas. A refeição foi composta por dois itens, em embalagens unitarias: arroz e carne bovina com legumes. A formulação do arroz foi composta por agua (54%), arroz parboilizado (32%), cebola (8%), oleo (4%), sal (1%) e alho (1%). A carne com legumes foi formulada com cubos de carne (35%), selada, pre-processada por imersao em oleo vegetal a 178°C por 3 min., molho de carne (29%), batata (22%) e cenoura (14%) em cubos. Foram utilizados 3 tipos de embalagens laminadas, pre-formadas, com picote para abertura manual e capacidade de 250 g de produto, sendo duas com estrutura auto-sustentavel (uvcpf"wr"rqwej) e uma do tipo envelope de quatro soldas (hncv). A caracterização das embalagens foi realizada por medidas dimensionais, propriedades de barreira (taxa de permeabilidade ao oxigenio e ao vapor de agua), propriedades mecânicas (resistencia a tracao e estouro) e inspecao visual de defeitos. As analises microbiologicas foram realizadas para avaliacao da carga microbiana inicial das materias-primas e obtencao de dados iniciais, para verificacao da eficiencia do processo de esterilizacao. O tratamento termico foi realizado em autoclave de imersao com F0 de 14 min. As refeicoes foram submetidas a analise sensorial atraves de teste de aceitacao de escala hedonica para aparencia, sabor, aroma e impressao global e testes de aceitacao de escala do ideal para textura do arroz, carne bovina e legumes e gosto de sal. Os testes foram conduzidos com 140 homens, militares da Aeronautica, distribuidos nas guarnicoes do Amazonas, Rio Grande do Sul, Rio de Janeiro e Sao Paulo. Os resultados do teste de escala hedonica indicaram que o tipo de embalagem nao influenciou na aceitacao da refeicao (p<0,05), sendo que pelo menos 60% dos provadores atribuiram notas maiores ou iguais a cinco para os atributos aparencia, sabor, aroma e impressão global. No teste da escala de ideal verificou-se que pelo menos 80% dos provadores consideraram a textura da carne entre os termos -1 e +1, a textura dos legumes entre -1 e +1, a textura do arroz entre -1 e +1 e o gosto salgado entre ¿1 e +1. Isto indica a aceitação sensorial da refeição. Os experimentos demonstraram a satisfacao dos militares e puderam servir de fundamento para o atual emprego das rações operacionais no ambito da Força Aerea Brasileira / Abstract: The operational meals means are fundamental to the implementation of the activities of training and actual deployment of the armed forces around the world and is still employed in circumstances of contingency of civil order. In this sense, the Brazilian Air Force, in the search for solutions and continuing improvements in the area of the food supply, is prioritizing the research and development into products ready for consumption. The main objective of the research was to develop a meal ready for consumption in sterile flexible packaging to aircraft crews and land use to replace the system currently used by the Armed Forces. The board was composed of two items on individual packages: rice and meat with vegetables. The wording of the rice was composed by water (54%), rice (32%), onion (8%), oil (4%), salt (1%) and garlic (1%). The meat with vegetables was made with cubes of meat (35%), stamped, pre-processed by immersion in vegetable oil to 178 ° C for 3 min., sauce, meat (29%), potatoes (22%) and carrot (14%) in the cubes. We used 3 types of packaging rolled, pre-formed, for manual opening and capacity of 250 g of product, and two with structure self-sustaining (stand up pouch) and an envelope of the type of four solders (flat). The characterization of the packaging was done by measurements dimensional, property of barrier rate (permeability to oxygen and water vapor) and mechanical properties (tensile strength and burst test) and visual inspection of defects. Microbiological analyses was made for evaluation of the initial microbial load of raw materials and obtaining initial data references for verification of the efficiency of the process of sterilization. The heat treatment was carried out in retort of immersion with F0, 14 min. Meals were subjected to analysis by means of sensory test of acceptance of hedonic scale for appearance, flavor, aroma and overall impression, and acceptance tests of scale of the ideal texture to the rice, meat and vegetables and taste of salt. The tests were conducted with 140 men, soldiers of Aeronautics, distributed in trimmings of Amazonas, Rio Grande do Sul, Rio de Janeiro and São Paulo. The results of the test hedonic scale indicated that the type of packaging not influenced the acceptance of the meal (p <0.05), of which at least 83% of the judges assigned notes greater than or equal to five to the attributes appearance, flavor, aroma and overall impression. In the ideal test of the scale of it was found that at least 62% of the tasters found the texture of the meat, vegetables and rice, and the salty taste ideals. The experiments demonstrated the satisfaction of the military and could serve as the basis for the current employment of operational meals of the Brazilian Air Force / Mestrado / Mestre em Tecnologia de Alimentos

The object of this research was to develop a retort for research and development of thermal processes which use common commercial thermal processing techniques. An FMC 500W laboratory sterilizer, designed to operate with an FMC weir product racking system, was modified for conventional steam, positive flow steam/air and water immersion/air overpressure thermal processing of foods in thin profile retortable packages. The research included the modification of the retort plumbing and the fabrication of a set of product trays and a racking system. The completed system was tested for temperature distribution and stability, and heat transfer distribution for each processing mode. The latter was achieved by comparing the heat penetration parameters calculated from the centerpoint temperature histories of conduction heating teflon transducers. / Applied Science, Faculty of / Graduate