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| Author(s): |
Adriana Torres Silva
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos |
| Defense date: | 2003-03-06 |
| Examining board members: |
Ariene Gimenes Fernandes Van Dender;
Airton Vialta;
Eliana Paula Ribeiro;
Salvador Massaguer Roig;
Mirna Lúcia Gigante;
Eliete Vaz de Faria
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| Advisor: | Ariene Gimenes Fernandes Van Dender |
| Abstract | |
The main objective of this research project was to study the viability of replacing fermentation of ultrafiltration retentates with direct acidification (Iactic acid) in the manufacturing process of requeijão cremoso and requeijão cremoso light made by ultrafiltration (UF). The study was carried out in two phases: the first with full-fat, regular requeijão cremoso and the second with requeijão cremoso light (reduced fat). 80th products were obtained from UF retentates. The fist phase consisted of two experiments with full-fat requeijão cremoso. The first experiment aimed at gaining a better understanding of the characteristics of the UF product, whereas the primary objective of the second experiment was to study direct acidification of UF retentates with lactic acid for the manufacture of UF requeijão cremoso. In both cases, the products were compared to requeijão cremoso made from curds obtained by direct acidification of heated whole milk (traditional requeijão cremoso). The second phase involved two experiments with requeijão cremoso light. The primary focus here was to study and leam more about some processing parameters of the manufacturing process of traditional requeijão cremoso light, Le. the product made from curds obtained by direct acidification of heated skim milk. Next, the processing conditions and parameters determined in the foregoing part were used as point of departure to evaluate the viability of manufacturing requeijão cremoso light from retentates obtained by ultrafiltration of skim milk and directly acidified with lactic acid. The resulting product was then compared to both traditional requeijão light and requeijão made from fermented UF retentates. All the products manufactured for the purpose of this study were analyzed as to their sensory attributes and physical, chemical and microbiological characteristics at regular intervals during 120 days storage at refrigeration temperatures. The results produced in the first experiment of the first phase of this research project show that UF requeijão cremoso presents lower pH values and higher fat, total dry matter, ash, soluble nitrogen, Ca and Mg levels, in addition to firmer body as compared to traditional requeijão. On the other hand, both products exhibited similar sensory characteristics. Microbiological quality of both requeijão types was satisfactory even after 60 days storage, which is the shelf life of the commercial product. In the second experiment of the first phase, the use of retentate directly acidified with lactic acid to pH 5,5 proved to be a viable altemative of easy practical application in the manufacture of UF requeijão cremoso. ... Note: The complete abstract is available with the full electronic digital thesis or dissertations. (AU) | |