Effect of milk processing and steam frothing conditions on microfoam formation.

This study focuses on the evaluation of microfoam produced from processed dairy milk using the steaming function of the espresso machine as a function of temperature (30 – 80°C), milk type (pasteurised or UHT), and whey protein contents. Foam characteristics, i.e., foam stability, viscosity, bubble size distribution noticeably varied depending on milk processing type and steam heating temperature. Foams made from pasteurised whole milk tend to be more stable. Bubbles in pasteurised milk foam were better distributed, especially at the temperature of 60°C. It was observed that the optimal final temperature of steam frothing was in the range of 50°C to 60°C. The results of sensory tests show that consumers differentiated between the aroma and flavour of pasteurised and UHT milk, describing the degree of this difference from moderate to strong. The technique of freeze-distilling (FD) milk was first used at the World Barista Championship 2017. This method is mainly used to intensify the flavour of milk by reducing the amount of water in the milk. The analysis of freeze-distilled milk samples demonstrated the increase in protein and lactose concentration in both pasteurized and UHT milk samples. Particle size distribution was not significantly affected by freezing of milk samples within 24 h with the subsequent thawing. Freeze-distillation also showed no significant effect on milk foaming properties in terms of microfoam expansion, stability, and overrun. The results of the triangle test showed that panellists could distinguish between cappuccino samples made with regular and freeze-distilled milk for both pasteurized and UHT milk types. Assessors described freeze-distilled samples as sweeter, more intense, and rich

Vitamins in Human and Donkey Milk: Functional and Nutritional Role

Background: Whole milk is a good source of all the nutrients, and it also contains a sufficient number of vitamins to permit regular the growth of the neonate. Dairy cow milk can create allergy in infants less than 12 months old because of the high caseins and β-lactoglobulin content. In these circumstances, donkey milk can represent a good replacement for dairy cows’ milk in children affected by Cow Milk Protein Allergy (CMPA) because of its close chemical composition with human milk, mainly due to its low protein and low mineral content. Milk vitamin content is highly variable among mammalian species and it is strictly correlated with the vitamin status and the diet administered to the mother. Fat-soluble vitamins content in donkey milk is, on average, lower compared to ruminants’ milk, while vitamin C content determined in donkey milk is higher compared to dairy cows’ milk, showing a great similarity with human milk. In donkey milk, the content of vitamins of the B-complex such as thiamine, riboflavin, niacin, pyridoxine, and folic acid is higher compared to human milk. The use of donkey milk as a new functional food must be further evaluated in interdisciplinary clinical trials in which pediatricians, dietitians, and food scientists must be involved to deepen the knowledge about the positive health impact of donkey milk in different sensitive people, especially children and the elderly

Effects of different steam injection conditions on cappuccino's nutritional profile

The quality parameters of cappuccinos prepared with pasteurized milk or ultra-high-temperature milk steam-injected at different temperatures by a professional coffee machine have been assessed. In particular, the protein profile, the content of vitamins and lactose, the lipid peroxidation process, and the involvement of milk proteins in the foam formation were evaluated. The nutritional quality of milk seems not affected by the steam injection treatment carried out at a temperature of 60–65 °C, but at higher temperatures a decrement of lactoperoxidase, vitamin B6 and folic acid was observed. The milk used in cappuccino preparation is very important: pasteurized milk can form a more consistent and lasting foam with respect to ultra-high-temperature milk because of the presence of β-lactoglobulin and lactoferrin, both playing an important role in the foam formation and stability. This work would provide additional information to the coffee industry for the preparation of high nutritional and organoleptic quality cappuccinos

The Effects of Donkey Meay Cooking Processes on Vitamins and Minerals Content.

Meat is an important source of minerals and vitamins, and for this reason largely contributes to the daily intakes of these micronutrients in human diet. Meat cooking techniques showed significant effects on vitamin and trace element contents, with important losses of B-vitamins. Losses in minerals after cooking occur, too, so the amounts of these nutrients really ingested with meat intake could vary greatly. Donkey meat minerals level has been previously determined, while vitamins content has never been evaluated in this kind of red meat. The aim of the present study was to detect minerals and vitamins B-complex content in raw donkey meat and to analyze the influence of cooking process on the level of these micronutrients. Twelve male entire crossbred donkeys born and reared in the same farm were slaughtered at 20 months of age, with an average final body weight of 246±20 kg. After slaughtering four samples of 600 g were taken from the muscle Longissimus thoracis (LT). Two samples of LT were used for raw meat chemical analysis, the other two LT samples were cooked in an oven at 170 °C for 45 min. B-vitamins were quantified by HPLC, while macro (Ca, K, Mg, Na, P) and microelements (Cu, Mn, Fe, Zn) were determined by means of atomic absorption spectroscopy. Data were analysed by the method of least squares using the GLM procedure. Niacin content was the most abundant vitamin determined in raw meat, 6.9±0.27 mg/100 g, followed by pantothenic acid, 1.13 mg/100 g, vitamin B6, 0.61±0.12 mg/100 g, then riboflavin, 0.22±0.07 mg/100 g. Thiamine content was 0.09±0.01 mg/100 g, vitamin B12 content was 1.8±0.15 μg/100 g. Cooking procedure decreased B-vitamins complex content, mainly thiamine, that resulted significantly reduced (trace) by thermal degradation. Niacin content showed a significant (5.22±0.16 mg/100 g) decrease after cooking; riboflavin resulted more stable to heat. Vitamin B12 showed a significant (1.10±0.04 mg/100 g) decrease in cooked donkey meat. Potassium is the most abundant mineral in raw donkey meat (375±23.4 mg/100 g), followed by phosphorus (261±14.4 mg/100 g) and sodium (44.7±2.11 mg/100 g). Considering the microelements, in raw meat iron content was 2.87±0.28 mg/100 g, while zinc was 5.60±1.01 mg/100 g. Cooked donkey meat did not show significant decrease in iron and zinc content compared to raw meat. Copper remained quite stable after cooking process, and the other minerals did not show significant differences

Effects of Ageing on Donkey Meat Chemical Composition, Fatty Acid Profile and Volatile Compounds

Donkey meat samples obtained from muscle Longissimus Thoracis Lumborum (LTL) taken from 14 entire donkey males slaughtered at 20 months and aged for 1, 8 and 15 days were analysed with the aim of determining the chemical composition, physical attributes, fatty acid profile and volatile compounds. Ageing did not significantly affect the chemical composition and colour parameters, while cooking loss was significantly (p < 0.05) higher at 8 and 15 days of ageing. Thiobarbituric acid reactive substances (TBARS) content significantly (p < 0.01) increased during ageing, while shear force values significantly (p < 0.01) decreased. Ageing significantly (p < 0.05) increased polyunsaturated fatty acids (PUFAs) determined both at 8 and 15 days after slaughter. Volatile compounds were analysed using solid-phase microextraction (SPME) and gas chromatography–mass spectrometry (GC–MS). Among 109 volatile compounds determined in donkey meat, hydrocarbons were the most common molecules detected. Ageing affected 21 of the detected volatile compounds; both total aldehydes and total ketones contents were significantly (p < 0.05) higher 15 days after slaughter. Total furans and total alcohols were significantly (p < 0.01) higher 15 days after slaughter, as well. Significant modifications of donkey meat volatile compounds can be attributed to ageing periods longer than 7 days

Effects of Donkeys Rearing System on Performance Indices, Carcass, and Meat Quality

This study compared growth rates, carcass, and meat quality obtained from 24 male crossbred donkey foals reared for meat production under an intensive (I) or extensive (E) feeding system. Donkeys were slaughtered at 16 months of age; the average final body weight, hot and cold carcass weight, and hot and cold dressing percentage were significantly higher (p < 0.05) in the I group. Samples of Longissimus Thoracis et Lumborum (LTL) were taken from each foal for chemical and physical analysis. Group I showed significant (p < 0.05) higher intramuscular fat, while the E group showed significantly (p < 0.05) higher protein and unsaturated fatty acids (UFA) contents, including n-3 essential fatty acids. Saturated fatty acids (SFA) and glycogen were significantly higher (p < 0.05) in the intensive system, monounsaturated fatty acids (MUFA) were significantly higher in the extensive system. The ratio PUFA/SFA was significantly higher (p < 0.05) in group E. The Thrombogenic Index (TI) was significantly higher (p < 0.05) in the I group. Meat tenderness was significantly higher (p < 0.05) in group I. The feeding system had no effect on cholesterol content and meat color characteristics. Donkeys average daily gain, carcass weight, and some meat quality parameters were significantly affected by the rearing system

Water- and fat-soluble vitamins in milk after different thermal treatments and steam injection.

To prepare a good cappuccino, it is preferable to use fresh whole milk as its high-fat content contributes to the flavour and its protein content is useful for a good whipping of the milk contributing to its creaminess. The foam is produced by the nozzle of the coffee machine, which is necessary to obtain a compact cream, but it is also important that the temperature of the milk must not exceed 65-70°C, to avoid an unpleasant aroma and the lack of foam formation. Furthermore, the nutritional quality of the milk should remain unchanged after the steam injection treatment. In the present work, we focused the attention on the water- and fat-soluble vitamins content in pasteurized bovine milk samples (HQ-milk) treated at different temperatures (40-80°C) and steam injected pressure using a nozzle of Simonelli Group coffee machine. The treatment time was 20, 30, 40, 50, and 60 seconds. Water- and fat-soluble vitamins content on the treated HQ-milk has been determined by RP-HPLC using a C18 column (HiQSil C18 HS, 5 μm, 4.6 mm i.d, 250 mm, Kya Tech Corporation), connected to an HPLC Agilent 1260 Infinity LC System (Agilent Technologies), according to two different protocols from Albalá-Hurtado and co-workers [1, 2]. Quantification was achieved by a calibration curve obtained relating the concentrations (M) of each vitamin standard loaded in the column to the peak area corresponding to each concentration. The results showed that if the only temperature is applied, vitamin B2, nicotinic acid, and nicotinamide were not affected by the increasing temperature because the exposure time from 20 to 60 seconds is too short to cause a decrement in the vitamins content. However, when the HQ-milk is treated with increasing temperature together with steam injection, an interesting result regarding the nicotinic acid concentration was obtained. In fact, the concentration of nicotinic acid increases by about 6.5 folds starting from 7.5 M at 25°C to reach a mean value of 45 M at a temperature range of 50-70°C. It is also interesting to note that the increase of nicotinic acid concentration is time-dependent: if the HQ-milk is treated for 20 seconds with the steam injection (time normally used to heat the milk during the preparation of the cappuccino), nicotinic acid reaches its highest concentration (54 M) at 70°C, but if the milk is treated for 60 seconds, the highest concentration (43 M) is reached at 50°C. Nicotinic acid (Niacin) is used to prevent and treat niacin deficiency that may result from alcohol abuse, malabsorption syndrome, Hartnup disease, poor diet. Furthermore, nicotinic acid is used to treat dyslipidemias since reduces triglycerides and LDL cholesterol and raises HDL cholesterol levels [3]. In our experiments, we observed that the increase in nicotinic acid dependent on the steam injected and the treatment time is accompanied by a simultaneous decrease in quinolinic acid. The latter is generated within the kynurenine pathway resulting from L-tryptophan catabolism and may be present in the milk since it is related to the composition of the cows’ diet [4]. Quinolinic acid may be converted to nicotinic acid by a decarboxylation reaction induced by the temperature and the steam injected pressure [5]. However, this hypothesis needs to be further confirmed. On the contrary, nicotinamide and B6 decrease when temperature and steam injection increased, whereas vitamin B2 resulted not affected by the treatment. Among fat-soluble vitamins, the results showed that vitamin E and vitamin D3 did not undergo variations after temperature and steam injection treatment while vitamin A was slightly affected. In conclusion, these results indicate that the nutritional quality of HQ-milk, from the point of view of the concentration of vitamins, seems not influenced by the thermal treatment and by the injected steam. It was observed, after this treatment, an increase in milk nicotinic acid content, very interesting considering the beneficial effects on human health exerted by this vitamin

Nutritional Parameters in Colostrum of Different Mammalian Species

Colostrum (or first milk) is the food produced by all the mothers in all specific mammalian species, ruminants, monogastric and marine mammalians for their newborns during the first 24–48 h post-partum. Colostrum provides to the neonate all essential nutrients necessary for the first week of life, but the effect of colostrum shows a long-term effect not limited to these first days. Colostrum is considered to be a safe and essential food for human consumption. Some young children can show at the beginning of their colostrum-based diet some side effects, such as nausea and flatulence, but they disappear quickly. In human colostrum, the immunoglobulins and lactoferrin determined show the ability to create natural immunity in newborns, reducing greatly the mortality rate in children. Recent studies suggest that bovine colostrum (BC) may be an interesting nutraceutical food, due to its ability in preventing and/or mitigating several diseases in newborns and adults. This review aims to show the nutraceutical and functional properties of colostrum produced by several mammalian species, describing the different colostrum bio-active molecules and reporting the clinical trials aimed to determine colostrum nutraceutical and therapeutic characteristics in human nutrition

Nutritional Properties of Camelids and Equids Fresh and Fermented Milk

Milk is considered a complete food because all of the nutrients important to fulfill a newborn’s daily requirements are present, including vitamins and minerals, ensuring the correct growth rate. A large amount of global milk production is represented by cow, goat, and sheep milks; these species produce about 87% of the milk available all over the world. However, the milk obtained by minor dairy animal species is a basic food and an important family business in several parts of the world. Milk nutritional properties from a wide range of minor dairy animal species have not been totally determined. Hot temperatures and the lack of water and feed in some arid and semi-arid areas negatively affect dairy cows; in these countries, milk supply for local nomadic populations is provided by camels and dromedaries. The nutritional quality in the milk obtained from South American camelids has still not been completely investigated, the possibility of creating an economic resource for the people living in the Andean highlands must be evaluated. Both mare and donkey milks show a chemical composition very similar to human milk, and they represent a good replacer of cows’ milk for infants nutrition, especially for children affected by cow milk proteins allergy. In this review, differences and similarities in the quality parameters of milk from minor dairy animals, such as camelids and equids, have been compared

Nutraceutical and Functional Properties of Camelids’ Milk

In most areas of the world, camelids are considered exotic animals, living only in zoological gardens. Additionally, considering the original lands where they were previously bred with specific economic and social aims, today it is possible to detect a reduction in their total numbers. Typically bred as working animals for goods transportation in desert regions, and as a source of meat and milk, in recent years, camels have been dismissed due to the construction of new roads for motor vehicles, the migration of nomadic populations from deserts to urban zones, and the choice of some autochthonous bovine breeds as sources of meat and milk. The decline in camelids heads seems irreversible. Camels should be considered a valid source of food in marginal areas; the peculiar quality parameters of their milk, showing the proper characteristics for the use of this milk in human nutrition, can justify the choice for breeding them, rather than considering camels only as objects of amusement