MINISTRY OF EDUCATION AND TRAINING HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING CAPSTONE PROJECT FOOD TECHNOLOGY DEVELOPING FREEZE-DRIED SNACK BITES FROM KEFIR MILK LECTURER: Dr. CAO THI THANH LOAN STUDENT: NGUYEN THI YEN LINH DOAN THI UT NHI SKL 0 0 8 4 5 0 Ho Chi Minh City, December, 2021 HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING FOOD TECHNOLOGY GRADUATION PROJECT CODE:2021-17116019 DEVELOPING FREEZE-DRIED SNACK BITES FROM KEFIR MILK Advisor: Dr. CAO THI THANH LOAN Student ID NGUYEN THI YEN LINH 17116019 DOAN THI UT NHI 17116025 Ho Chi Minh City, 23th December 2021 ii i ii iii iv v vi vii viii ix x xi Acknowledgement for Thesis Foremost, we would like to express our sincere gratitude to our advisors Dr. Loan Cao, visiting lecturer at the Faculty of High Quality at Ho Chi Minh City University of Technology and Education.
During the research and writing of this thesis, Dr. Loan Cao has enthusiastically supported, guided and given advice from her rich knowledge and rich experience. Her guidance helped us gain experience and learn many useful things to apply to the research and development of this thesis. We would like to thank Dr.
Pham Thi Hoan, lecturer at the Faculty of High Quality at Ho Chi Minh City University of Technology and Education. Her enthusiastic support at any time helped us complete the research and development of this thesis. We are truly grateful to her for enthusiastically supporting and imparting knowledge during our study at Ho Chi Minh City University of Technology and Education We would like to thank the lecturers of the Faculty of Food and Chemical Technology at Ho Chi Minh City University of Technology and Education for their enthusiastic support and providing favorable conditions for us to do research in the laboratory with modern equipment. Last but not the least, we would like to thank Kefir Home company for providing knowledge and materials to research this thesis.
We would also like to thank our family and friends who have always encouraged and supported us to overcome difficulties during the process of researching this thesis. xii Disclaimer I proclaim that all content presented in this thesis is our own. I declare that all references in the graduation thesis have been correctly and completely cited in accordance with regulations. Ho Chi Minh City, December 23, 2021 xiii Table of Contents Acknowledgement for Thesis.
xviii Chapter 1: INTRODUCTION. Object and scope of the study. Scientific and practical significance. Overview about snack foods.
Nutritional value of Snack foods. Types of snack foods. The snack food market. Overview about kefir milk and kefir grains.
Overview about freeze-drying process. 12 Chapter 3: MATERIALS AND METHODS. Materials, chemical and equipment. Kefir Milk production.
Layout diagram of research procedures. Evaluated the effects of ingredients on the fermentation process and quality of kefir milk .2 Formulate the milk-kefir snack bites. Determine the parameters of the snack bites and evaluate sensory of the product. Determine the storage time and packaging of the snack bites.
35 xiv Chapter 4: EXPERIMENT RESULTS. Evaluated the effects of ingredients on the fermentation process and quality of kefir milk. Formulate the milk-kefir snack bites. Determine the parameters of the snack bites.
Analysis nutrition of snack bites. 52 Chapter 5: CONCLUSION AND RECOMMENDATIONS. 65 xv List of figures Figure 2. Nutrient contents of Commercial Snack Food Products.
Different shaped snack. Third-generation snacks foods. First-generation snack foods. Second-generation snack foods.
Snack food market: Year-on-year Growth Rate (%), Global, 2014-2019. Value of the savory snacks market in Vietnam from 2019 to 2026 with forecasts until 2026. Flowchart of freeze-drying process. Flowchart of Kefir Milk production………….
Layout diagram of research procedures. Flowchart of snacks production. Electronic digital caliper. Snack bites hardness measurement by Texture Profile Analysis (TPA).
Chroma meter CR- 400 and white calibration plate. Store in 3 types of packaging at room temperature. Growth of a 5-day old culture of yeast grown on DRBC medium. Growth of a 2-day old culture of Lactobacillus spp.
grown on MRS medium. The streak culture isolates of Lactobacillus spp. Trend of hardness of each snack sample for 14 days stored in three different packaging. 45 xvi List of tables Table 3.
Nutritional information of cow’s milk [50]. Nutritional information per 100 ml Vinamilk. Nutritional information per 100 ml DaLat milk. Nutritional information per 100 ml Pure milk.
Composition of Powdered sugar. Ingredient of Milk powder. Elements and ingredients recipe for the preparation of kefir milk fermentation 24 Table 3. Mixing recipe for snack production.
Parameters of snack bites texture measurement. White calibration parameters of the handheld colorimeter CR-400/410. Criteria for evaluate color based on ∆E [74]. Analysis nutrition of snack bites.
The results of biomass analysis…………………………………………………. The result of sensory evaluation. The result of physical analysis. The parameters of the snack bites.
The results of the snack hardness for 14 days were stored in three different packaging. The results of the snack lightness for 14 days were stored in three different packaging. The results of the snack redness for 14 days were stored in three different packaging. The results of the snack yellowness for 14 days were stored in three different packaging.
The results of ∆E of snacks color for 14 days were stored in three different packaging. The results of sensory evaluation of snack samples. Analysis nutrition of snack bites. Evaluation of chemical composition between Freeze-dried snack bites from kefir milk containing gelatin - sugar and Freeze-dried snack bites from yogurt (containing modified starch).
Quantification of Lactobacillus spp. and total yeast in snack bites. 54 xvii Abstract In this study, kefir grains were fermented with 3 different types of milk such as Vinamilk, Da Lat milk, and Greendale Pure Milk Full Cream with the ratio of kefir grains and milk ratio is 7% (wt/ml) for two periods 16 hours and 24 hours. The products kefir milk after fermentation is determined quality through sensory testing, pH and moisture measurement, microbial identification by microbial culture method.
The results showed that Vinamilk milk at 16 hours reached the most optimal level to the quality of kefir milk, from which to conduct a survey of the mixing formula to choose the best quality product. The quality of the snack bites will be evaluated through parameters from the method of determining moisture, weight, thickness, hardness, color, sensory. After mixing and freeze-drying, the weight and thickness of the samples showed no significant difference between the survey samples, but there is a clear difference between the survey sample and the control sample. In terms of moisture content and sensory, the results show differences between samples based on different ingredients.
Moreover, because there is a difference between the properties of the mixing ingredients, the hardness and color of the product are markedly different. After surveying, we chose the best quality product, Gelatin- Sugar, to determine nutrition and total microbial in snack bites products. Furthermore, when storing products in 3 different types of packaging, the results show that the quality of products preserved by aluminum foil packaging is no less than vacuum LDPE packaging, but because of its popularity and easy packaging techniques, we choose aluminum foil packaging as the most optimal packaging. Keywords: Kefir milk, snack bites, probiotic, freeze-dried.
xviii Chapter 1: INTRODUCTION 1. Rationale Snack foods have always been a vital element of the food industry and modern life in recent years, according to the current global trend. The current trend in food selection is for quick-to-process foods that meet cleanliness, safety, and quality as well as energy requirements. Snacks have evolved into necessary foods for both children and adults, thanks to the emergence of hundreds of distinct ingredients.
Snack goods can be classed based on the raw materials used to make them, such as vegetables, fruits, and flour, and they can be made in a variety of ways to provide full nutrition and a sturdy structure, such as frying, baking, extruding, roasting, or freeze-drying. When consumers' health is a top priority, they will look to change their meals to fit a healthier lifestyle. Kefir is one of the long-standing unique nutritious and tasty components when it comes to its rich concentration of probiotics, proteins, and digestive aids known to consumers, is one of the greatest suggestions for consumers. Kefir have high in calcium, magnesium, vitamins B2, B12, A, D, and K, phosphorus, minerals, amino acids, and enzymes, as well as other useful bacteria [25].
Kefir contains a high amount of antioxidants and so has therapeutic benefits. Furthermore, it provides various physiological benefits, including skin health, digestion, weight loss, and lactase enzyme management [95]. Smoothies and sauces can be made with kefir. These reasons contribute to kefir's gradual rise in popularity.
As a result, during the awareness period, the market is expected to increase at a significant rate. The current problems in the snack industry are to provide healthier snacks (mostly by reducing fat, sodium, and sugar) while maintaining the snack industry's traditional quality features. One of the safest and effective snack processing methods to create the best quality snack is freeze-drying. Freeze-drying keeps more nutritional content than other drying processes, ensuring that whole foods retain their nutritious worth.
This method also preserves the actual shape and color of the original materials, ensuring that consumers feel real fruits and vegetables in their diets. Another benefit of freeze-drying is the opportunity to customize it to your specific requirements and project objectives. Frozen ingredients can be created in a variety of sizes and shapes from fruits and vegetables to a fine flour. The last product can be easily mixed into any mixture or recipe to give the end product a unique flavor [39].
The digestive system in humans is a system that has a complex structure, easily disturbed when we do not fully tolerate nutrients to balance them, especially the digestive system of children and the elderly when children's stomachs are not yet developed while the elderly has deteriorated leading to more easily upset digestion. With the special benefit of kefir containing many beneficial yeast such as Saccharomyces kefiri and Torular kefir [92] these two enzymes penetrate the mucous membrane where harmful bacteria are formed, forming Special Weapons And Tactics (SWAT) group that removes harmful bacteria and the intestinal tract. we have researched a novel product through freeze-drying intending to create a new rich product nutritious and good for health especially for children and the elderly, those with poor digestive systems have a nice life and live healthier. Objection The purpose of the thesis “Developing freeze-dried snack bites from kefir milk” is to formulate a healthy freeze-dried foodstuff using kefir as the main ingredients, as well as to evaluate the sensory and nutrient features of kefir based freeze-dried product.
Object and scope of the study The study investigated the influence of different types of milk on the quality of kefir milk and the changes of kefir milk after mixing with different ingredients. Analysis of the influence of ingredients on color, moisture, size, texture, and sensory quality of snack bites after freeze-drying. From there, a suitable method is proposed to produce the best product while retaining the inherent nutritional value. Research content The topic “ Developing freeze-dried snack bite from kefir milk” includes the following specific contents: Experiment 1: Evaluated the effects of ingredients on the fermentation process and quality of kefir milk.
In this study, biomass analysis of kefir grains, sensory evaluation, physicochemical analysis, and biological analysis of kefir milk were collected. Experiment 2: Formulate the kefir milk snack bites. Experiment 3: Determine the parameters (moisture content, weight, thickness, hardness, color, nutrients, microbiological quantification) of the snack bites and evaluate sensory of the product.