Optimization of Donkey Milk Pasteurization Process
- 34 Downloads
Donkey milk represents an attractive solution as new-born feeding, mainly if occur physiological limitations concerning the milk availability in post-pregnancy or bovine’s milk proteins linked to immune diseases. At present, the producers use custom-made batch pasteurization plant, with a poor temperature control system and very high time required to carry out the pasteurization process. It is due to the low availability of raw materials due to limited donkey livestock and low milk’s yield and the lack of high technology UHT pasteurization plants with limited processing capacity. In this work, an innovative low capability (30 l/h) continuous flow pasteurization plant, designed and built for High Temperature for Short Time (HTST) treatments, was characterized in the MACLab of UNIBAS. To test the plant, a matrix with three pasteurization temperatures (75, 85, 92 °C) and times (3, 7, 14 s) was tested, and the efficacy of the treatments was evaluated on microflora enumeration (L. monocytgenens, Enterobacteriaceae, total aerobic bacteria) as soon as after the treatments and over 30 days-storage at 4 °C. The HTST apparatus showed high performance; the complete eradication of Enterobacteriaceae detected the efficacy of the treatments at every time and temperatures tested. Decreasing in total bacterial count and lysozyme content was affected by treatment size. Through this methodological approach, it was possible to investigate the effect of HTST treatments (following by cooling soon) on the primary chemical and microbiological standard for donkey milk, to set up an official sanitation protocol that allows optimizing its nutritional value.
KeywordsPlate heat exchanger Donkey milk Pasteurization HTST
- Altieri, G., Di Renzo, G. C., & Genovese, F. (2007). Spray dryer process performance optimization for producing milk powders from cow, goat and she-ass milk concentrates. In Food and agricultural products: Processing and innovations, 24–26 September. Naples, Italy.Google Scholar
- Altieri, G., Di Renzo, G. C., & Genovese, F. (2011). Preliminary evaluation of donkey’s milk properties through near infrared spectrometry. In Towards a sustainable food chain food process, bioprocessing and food quality management, 18–20 April. Nantes, France.Google Scholar
- Altieri, G., Genovese, F., Admane, N., & Di Renzo, G. C. (2016). On-line measure of donkey’s milk properties by near infrared spectrometry. Lebensmittel-Wissenschaft & Technologie, 69, 348–357.Google Scholar
- Di Renzo, G. C., Altieri, G., & Genovese, F. (2007). Tecniche per il trattamento del latte d’asina. Risultati di prove preliminari [In Italian: The she-ass milk treatment techniques. Preliminary results]. In Proceedings of II° Convegno Nazionale sul Latte d’Asina – “Latte d’asina perché”, Centro Congressi Coldiretti, Rome, 22 March.Google Scholar
- Di Renzo, G. C., Altieri, G., & Genovese, F. (2011). Prove preliminari per lo sviluppo di un sensore NIR per l’analisi dei parametri costitutivi nel latte di asina [In Italian: Preliminary trials for the development of a NIR sensor for the analysis of the donkey milk]. In Gestione e controllo dei sistemi agrari e forestali – Memorie, p. 36, Belgirate (VB), 22–24 September.Google Scholar
- European Pharmacopoeia 9.2 Supplement Implementation: 7/2017, Chapter 5.1.2 “Biological Indicators and related microbial preparation used in the manufacture of sterile products”.Google Scholar
- FAO/WHO. (2004). Code of hygienic practice for milk and milk products. Joint FAO/WHO Food Standards Programme-Codex Committee on Food Hygiene, 26th Session, March 29–April 2. Washington, DC, USA.Google Scholar
- Francis, D. W., Spaulding, P. L., Lovett, J. (1980). Enterotoxin production and thermal resistance of Yersinia enterocolitica in milk. Applied and Environmental Microbiolog, 40(1), 174–176.Google Scholar
- FDA. (2011). Fish and fisheries products hazards and control guidance, 4th ed. U.S. Food and Drug Administration, Department of Health and Human Services. Available at http://www.fda.gov/downloads/food/guidanceregulation/ucm251970.pdf.
- Gilbert, R. J., de Louvois, J., Donovan, T., Little, C., Nye, K., Ribeiro, C. D., Richards, J., Roberts, D., Bolton, F. J. (2000). Guidelines for the microbiological quality of some ready-to-eat foods sampled at the point of sale. Communicable Disease and Public Health, 3, 163–167. Google Scholar
- Lopes, R. P., Mota, M. J., Gomes, A. M., Delgadillo, I., & Saraiva, J. A. (2018). Application of high pressure with homogenization, temperature, carbon dioxide, and cold plasma for the inactivation of bacterial spores: A review. Comprehensive Reviews in Food Science and Food Safety, 17, 532–555.CrossRefGoogle Scholar
- Salerno, M., Paterlini, F., & Martino, P. A. (2011). Microbiologia e attività battericida del latte di asina. Latte d’asina: produzione, caratteristiche e gestione dell’azienda asinina, 193–205.Google Scholar