Dietary enrichment of milk and dairy products with n-3 fatty acids: A review

Composition and fatty acid profile of milk from cows fed diets supplemented with raw and n-3 PUFA-enriched fish oil

Dietary supplementation of ruminants with fish oil is a strategy for favorably modifying the fatty acid composition of milk fat. This study investigated the effect of supplementing cows' diet with fish oil after low-temperature crystallisation (LTC-FO) compared to its raw form (FO) on milk yield, milk components (fat, protein, and lactose), and milk fatty acid profile. Twenty-four mid-lactating multiparous Polish Holstein-Friesian cows fed a total-mix ration were randomly assigned to two homogeneous groups (n = 12 cows each) and supplemented with LTC-FO or FO at 1% of dry matter. Milk samples were collected on days 14 and 30 of the 30-day experiment. No significant differences between the groups in terms of milk yield, milk protein, and lactose content were found, however, the fat yield and content decreased in the LTC-FO group. Milk fat from cows in the LTC-FO group contained significantly higher levels of C18:1 trans-11, C18:2 cis-9, trans-11, C18:3n - 3, C20:5, and C22:6, and lower levels of saturated fatty acids compared to the FO group (p < 0.05). Therefore, LTC-FO may be a more efficient feed additive than FO and may serve as a practical way to modify the fatty acid composition of milk fat.

Changes in the rumen and milk fatty acid profile and milk composition in response to fish and microalgae oils supplementation to diet alone or combination in dairy goats

Dietary fat supplementation in the ruminant diet is known to be a good strategy to increase beneficial milk fat compounds such as polyunsaturated fatty acids (PUFA) and conjugated linoleic acid (CLA). To the best of our knowledge, this is the first study to compare and combine fish oil (FO) and Schizachyrium microalgae oil (MA) supplementation to the diets of dairy goats. This study aimed to investigate the inclusion of FO, MA, and their combinations in the diets for effects on performance, milk composition, milk fatty acids, ruminal biohydrogenation, and fermentation parameters in dairy goats. Four cannulated Saanen dairy goats in the second lactation with a daily 3.25 ± 0.10 L milk yield and 45.08 ± 0.5kg body weight were assigned to four treatments: (1) no lipid supplementation (CON), (2) supplementation with 20 g/kg of FO, (3) 20 g/kg of MA, (4) 10 g/kg FO + 10 g/kg MA (FOMA). Milk and fatty acid composition were determined in samples taken from three consecutive days of milking after 21 days of adaptation. On the same days, ruminal fatty acids were determined. Dietary oil supplementations did not affect the performance parameters in dairy goats. However, fat yield decreased in FOMA. The oil supplementations did not affect the milk composition. However, cholesterol in milk increased in FO (P < 0.05). C16:0 FA in milk increased in MA. C18:0 FA in milk was lowest in MA. The highest milk trans-11 C18:1 FA was in the MA group. Cis-9, trans-11 CLA, trans-10, cis-12 CLA, and ∑PUFA increased in milk with oil supplementations to diet. Milk ∑SFA was the lowest in the FO group. Ruminal C18:0 fatty acid was decreased in oil supplementations to diet. Ruminal trans-11 C18:1, cis-9, trans-11 CLA, trans-10, and cis-12 CLA were increased in oil-supplemented groups. Ruminal fermentation parameters were not affected by oil supplementation to diet; however, there was a propionate increase in the MA group. The serum glucose and cholesterol levels were not affected by oil supplementation to diet.

Nature's palette: An emerging frontier for coloring dairy products

Consumers all across the world are looking for the most delectable and appealing foods, while also demanding products that are safer, more nutritious, and healthier. Substitution of synthetic colorants with natural colorants has piqued consumer and market interest in recent years. Due to increasing demand, extensive research has been conducted to find natural and safe food additives, such as natural pigments, that may have health benefits. Natural colorants are made up of a variety of pigments, many of which have significant biological potential. Because of the promising health advantages, natural colorants are gaining immense interest in the dairy industry. This review goes over the use of various natural colorants in dairy products which can provide desirable color as well as positive health impacts. The purpose of this review is to provide an in-depth look into the field of food (natural or synthetic) colorants applied in dairy products as well as their potential health benefits, safety, general trends, and future prospects  in food science and technology. In this paper, we listed a plethora of applications of natural colorants in various milk-based products.

Enrichment of Ewe’s Milk with Dietary n-3 Fatty Acids from Palm, Linseed and Algae Oils in Isoenergetic Rations

Increasing the levels of n-3 fatty acids (FA) in dairy products is an important goal in terms of enhancing the nutritional value of these foods for the consumer. The purpose of this research was to evaluate the effects of linseed and algae oil supplements in ovine isoenergetic diets on healthy milk fatty acid composition, mainly n-3. Seventy-two Churra dairy ewes were divided and randomly assigned to four experimental treatments for 6 weeks. The treatments consisted of a TMR (40:60 forage:concentrate ratio) that varied according to the inclusion of different types of fat (23 g/100 g TMR): hydrogenated palm oil (control), linseed oil (LO), calcium soap of linseed oil (CaS-LO) and marine algae oil (AO). The most effective lipid supplement to increase n-3 FA in milk was AO. 22:6 n-3 and total n-3 PUFA content increased from 0.02 and 0.60% (control) to 2.63 and 3.53% (AO), respectively. All diets supplemented with n-3 FA diminished the content of saturated FA in milk and its atherogenic index, while the levels of trans-11 18:1 and cis-9 trans-11 18:2 significantly increased. Overall, the enhancement of n-3 FA in ewe’s milk would be advantageous for the manufacture of nutritionally improved cheeses.

Aquaculture and agriculture-by products as sustainable sources of omega-3 fatty acids in the food industry

The valorization of by-products is currently a matter of great concern to improve the sustainability of the food industry. High quality by-products derived from the food chain are omega-3 fatty acids, being fish the main source of docosahexaenoic acid and eicosapentaenoic acid. The search for economic and sustainable sources following the standards of circular economy had led to search for strategies that put in value new resources to obtain different omega-3 fatty acids, which could be further employed in the development of new industrial products without producing more wastes and economic losses. In this sense, seeds and vegetables, fruits and crustaceans by products can be an alternative. This review encompasses all these aspects on omega-3 fatty acids profile from marine and agri-food by-products together with their extraction and purification technologies are reported. These comprise conventional techniques like extraction with solvents, cold press, and wet pressing and, more recently proposed ones like, supercritical fluids fractionation and purification by chromatographic methods. The information collected indicates a trend to combine different conventional and emerging technologies to improve product yields and purity. This paper also addresses encapsulation strategies for their integration in novel foods to achieve maximum consumer acceptance and to ensure their effectiveness.

DHA-Rich Aurantiochytrium Biomass, a Novel Dietary Supplement, Resists Degradation by Rumen Microbiota without Disrupting Microbial Activity

We first sought to evaluate the effect of dietary supplementation with the docosahexaenoic acid (DHA)-rich microalgae, Aurantiochytrium limacinum (AURA), on rumen fermentation and the resistance of DHA to degradation and biohydrogenation by rumen microbes through ex vivo fermentation experiments. Subsequently, we sought to quantify the diet-derived DHA content of milk and the impact of AURA on microbial composition and metabolism in a pilot feeding trial with rumen-cannulated dairy cows. To achieve our aims, rumen fluid from cannulated cows was used as inoculum, and the effect of AURA inclusion on fermentation ex vivo was examined. At doses corresponding to the amount of AURA recommended for commercial production animals, only ~10% of DHA was degraded or biohydrogenated by rumen microorganisms. The results show that feeding with AURA had no effect on either total bacterial density or short-chain fatty acid production. Real-time quantitative PCR analysis of the rumen fluid samples collected during a seven-week in vivo trial revealed that microbes related to lactic acid metabolism and methanogenesis were significantly suppressed by the AURA-supplemented diet. The DHA concentration in milk increased over 25-fold with the AURA-supplemented diet and dropped by 30–40% within one week of washout. The addition of A. limacinum biomass to dairy cow diets resulted in positive effects on rumen microbial composition with no adverse effect on fermentation activity. AURA-derived DHA was stable, with only modest degradation in the rumen, and was successfully deposited in milk. This is the first study to investigate the effect of supplementing the diet of dairy cows with a protist-based biomass, namely, on important rumen fermentation parameters and on DHA deposition in milk, using a combination of ex vivo and in vivo approaches.

Dietary strategies to enrich milk with healthy fatty acids – a review

Feed is the main factor impacting the composition and quality of milk of dairy animals. Therefore, the present review explores the effects of feed and nutrition on milk fat content and levels of healthy fatty acids (FA) in milk consumed by humans. Milk and dairy products are two main sources of healthy and unhealthy FA in human nutrition. The concentrations of FA in milk depend mainly on diets; therefore, milk FA concentrations and ratios can be greatly altered by some feeding strategies. Dietary supplementation of the diets of dairy livestock with vegetable seeds or oils, microalgae and phytogenic feed additives, and feeding of some grasses can enhance the contents of healthy FA, including n-3 FA, α-linolenic acid, conjugated linoleic acid (CLA) and, generally, unsaturated FA in milk and dairy products. Enrichment of milk with healthy FA may make milk a source of anticarcenogens (CLA and polyphenols) for human health. This review, therefore, focusses on the current research findings on enrichment of milk with healthy FA and summarizes some effective supplementation strategies to alter milk FA profile.

Enzymes, In Vivo Biocatalysis, and Metabolic Engineering for Enabling a Circular Economy and Sustainability

Since the industrial revolution, the rapid growth and development of global industries have depended largely upon the utilization of coal-derived chemicals, and more recently, the utilization of petroleum-based chemicals. These developments have followed a linear economy model (produce, consume, and dispose). As the world is facing a serious threat from the climate change crisis, a more sustainable solution for manufacturing, i.e., circular economy in which waste from the same or different industries can be used as feedstocks or resources for production offers an attractive industrial/business model. In nature, biological systems, i.e., microorganisms routinely use their enzymes and metabolic pathways to convert organic and inorganic wastes to synthesize biochemicals and energy required for their growth. Therefore, an understanding of how selected enzymes convert biobased feedstocks into special (bio)chemicals serves as an important basis from which to build on for applications in biocatalysis, metabolic engineering, and synthetic biology to enable biobased processes that are greener and cleaner for the environment. This review article highlights the current state of knowledge regarding the enzymatic reactions used in converting biobased wastes (lignocellulosic biomass, sugar, phenolic acid, triglyceride, fatty acid, and glycerol) and greenhouse gases (CO₂ and CH₄) into value-added products and discusses the current progress made in their metabolic engineering. The commercial aspects and life cycle assessment of products from enzymatic and metabolic engineering are also discussed. Continued development in the field of metabolic engineering would offer diversified solutions which are sustainable and renewable for manufacturing valuable chemicals.

Calidad composicional y concentración de ácidos grasos omega-3 (alfa-linolénico) y omega-6 (linoleico) presentes en leche bovina de tres regiones naturales del Ecuador

La leche de vaca es un componente importante en la dieta humana y uno de sus aportes nutricionales es la fracción lipídica formada por diversos ácidos grasos, entre ellos, el ácido linoleico (AL) de familia omega-6 y el ácido alfa-linolénico (AAL) de familia omega-3, ambos constituyentes estructurales de membranas de tejidos celulares y reguladores metabólicos. Por su importancia, el objetivo de esta investigación fue determinar la concentración de ácidos grasos omega-3 (alfa-linolénico) y omega-6 (linoleico) mediante cromatografía de gases acoplada a espectrometría de masas (GC-MS), en relación con la influencia de los factores región (Costa, Sierra y Amazonía) y época (lluviosa y seca) sobre la concentración de dichos ácidos. Se trabajó con 30 centros de acopio y se recolectó según el protocolo LCL-INS-01. El análisis composicional se realizó bajo el método ISO 9622-IDF 141/2013 /LCL-PE-01 y el análisis del perfil lipídico mediante GC-MS. Los resultados obtenidos mostraron concentraciones (%) promedio de 2,72 y 0,06 para AL y AAL, respectivamente, en el perfil lipídico. En cuanto al factor región, Costa presentó 2,07%, Sierra 3,03% y Amazonía 3,06%, por lo que se evidenció alta diferencia significativa (p ≤ 0,01) para el AL, mientras que el AAL no mostró variación. En el factor época, el AL presentó 2,63% en época seca y 3,03% en época lluviosa, y el AAL 0,14 y 0,06%, respectivamente. Los resultados permitieron concluir que el factor región influye en la concentración del AL, pero no en el AAL, y el factor época no es influyente en la concentración del AL ni en la del AAL.

Quality, physicochemical, and textural properties of dairy products containing fruits and vegetables: A review

Due to the high utilization rate of dairy products, enrichment of these products will successfully decrease or prevent diseases related with nutrition deficiencies. Fruits and vegetables in different forms (i.e., fresh, juices, powder, puree, and extract) are excellent sources for the enrichment of dairy products because of their desired taste, color, aroma, fibers, and vitamins content. So, this manuscript reviews the effect of some fruits and vegetables on the rheological behavior, physicochemical attributes, color parameters, sensorial and quality properties of dairy products including cheeses, ice creams, and yogurts. The physicochemical, color, texture, and sensorial properties of dairy products were affected with addition of fruits or vegetables. Also, the addition of these products contributes to the higher content of vitamins, natural colorants, minerals, polyphenols, crude fiber, and carotenoids. In addition, some fruits and vegetables are considered as potential dairy products stabilizing agent due to their desirable functional properties, such as water binding and holding, gelling and thickening ability. In summary, enrichment of cheeses, ice creams, and yogurts with fruits and vegetables increase the market share of these products due to the high demand for goods for an improved diet, rich in compounds with antioxidant activity and biological properties.

Yogurt Enriched with Isochrysis galbana: An Innovative Functional Food

Microalgae are a valuable and innovative emerging source of natural nutrients and bioactive compounds that can be used as functional ingredients in order to increase the nutritional value of foods to improve human health and to prevent disease. The marine microalga Isochrysis galbana has great potential for the food industry as a functional ingredient, given its richness in ω3 long chain-polyunsaturated fatty acids (LC-PUFAs), with high contents of oleic, linoleic, alpha-linolenic acid (ALA), stearidonic, and docosahexaenoic (DHA) acids. This study focuses on the formulation of a functional food by the incorporation of 2% (w/w) of I. galbana freeze-dried biomass and 2% (w/w) of I. galbana ethyl acetate lipidic extract in solid natural yogurts preparation. In the functional yogurt enriched with microalgal biomass, the ω3 LC-PUFA's content increased (to 60 mg/100 g w/w), specifically the DHA content (9.6 mg/100 g ww), and the ω3/ω6 ratio (augmented to 0.8). The in vitro digestion study showed a poor bioaccessibility of essential ω3 LC-PUFAs, wherein linoleic acid (18:2 ω6) presented a bioaccessibility inferior to 10% and no DHA or eicosapentaenoic acid (EPA) was detected in the bioaccessible fraction of the functional yogurts, thus indicating a low accessibility of lipids during digestion. Notwithstanding, when compared to the original yogurt, an added value novel functional yogurt with DHA and a higher ω3 LC-PUFAs content was obtained. The functional yogurt enriched with I. galbana can be considered important from a nutritional point of view and a suitable source of essential FAs in the human diet. However, this needs further confirmation, entailing additional investigation into bioavailability through in vivo assays.

Hemp (Cannabis sativa L.) Seed and Co-Products Inclusion in Diets for Dairy Ruminants: A Review

Recently, hemp (Cannabis Sativa L.) was rediscovery as a plant that offers a wide variety of applications (textile, pharmaceuticals, construction, etc.), including also the use in animal and human nutrition. The inclusion of whole seeds and co-products obtained by processing of seeds (cake, meal, and oil) in the diets of farm animals can allow the transfer of bioactive substances to human food. Few publications are available on the use of hemp in dairy ruminants but some authors reported a positive effect on the fatty acids profile of milk and cheese with an increase of n-3 fatty acids and c9,t11 conjugated linoleic acid. The protein content, amino acids profile, and rumen undegradable protein (RUP) of hempseed and co-products of hemp appear interesting and suitable for ruminant nutrition. Negative effects of anti-nutritional factors (i.e., phytate) are not observed. However, the researches on the effects of the use of hempseed and co-products in diets for dairy ruminants do not allow to suggest optimal levels of inclusion. In addition, no data are published on the use of whole or part of the hemp plant as forage, as another possibility to use the hemp in the perspective of the circular economy.

Cheese fortification through the incorporation of UFA-rich sources: A review of recent (2010-2020) evidence

Cheese is a widely consumed dairy product with high saturated fatty acids (SFA) content, and with other high nutritional quality components. Due to the link of SFA and different diseases, many studies have replaced the cheese fat content with unsaturated fatty acids (UFA) rich sources to improve its nutritional quality. The fat replacement has physicochemical, textural, and sensory effects on dairy matrix. To the food science is mandatory to know which technological strategies of milk processing improve the quality of the end products. The most relevant results reveal that fish oil (FO) and flaxseed oil (FSO) have been the most researched UFA-rich sources, microencapsulation has been the most studied incorporation technology because it allows the oil entrapment with minimal effects on the cheese quality, and non-thermal technologies allow greater UFA fortification in cheese, improving its nutritional quality. Finally, the development of fortified cheeses with UFA-rich sources has been found as an innovative strategy to obtain high quality products with functional potential.

Effects of microwave heating on the chemical composition and bioactivity of orange juice-milk beverages

The effect of microwave heating (MH, 65 and 75 °C for 15, 30, and 60 s) on the bioactive compounds, fatty acid profile, and volatile compounds of orange juice-milk beverage (OJMB) was evaluated during 28 days of refrigerated (4 °C) storage. Conventionally pasteurized (75 °C/15 s) and untreated beverages were used as controls. MH-OJMB presented a lower browning index and higher levels of ascorbic acid, total phenolics, and carotenoids, higher antioxidant activity, and greater α-amylase, α-glucosidase, and ACE inhibitory activity than the pasteurized product, similar to the untreated beverage. No significant differences were observed in the volatile organic compounds and fatty acids levels. Lower temperatures (65 °C) and longer process times (60 s) resulted in higher retention of bioactive compounds. MH can be an alternative to conventional pasteurization for OJMB processing.

The Effect of Low-Temperature Crystallization of Fish Oil on the Chemical Composition, Fatty Acid Profile, and Functional Properties of Cow's Milk

The study aimed to investigate the effect of supplementation of fish oil after the process of low-temperature crystallization (LTC-FO) enriched with long-chain polyunsaturated fatty acids (LC-PUFAs) on cow milk parameters. The experiment was carried out on 24 Polish Holstein Friesian cows. For 4 weeks, experimental (EXP) group animals (n = 12) were fed LTC-FO (1% of dry matter). Milk was collected two times: on days 14 and 30. LTC-FO supplementation decreased milk fat yield and concentration (p < 0.01). Higher levels of polyunsaturated fatty acids (PUFAs), including these with beneficial biological properties, i.e., eicosapentaenoic (EPA), docosahexaenoic (DHA), docosapentaenoic (DPA), CLA, alpha-linolenic acid (ALA), and TVA (p < 0.01), and lower levels of SFAs, especially short- (p < 0.01) and medium-chain ones (p < 0.05, p < 0.01), were found in the EXP group. The addition of LTC-FO reduced the value of atherogenic and thrombogenic indices as well as SFA/UFA and n-6/n-3 ratios and increased the content of n-3 PUFA and functional fatty acids (p < 0.01). The addition of LTC-FO also increased the delta-9 desaturase index for CLA/TVA and decreased it for pairs C14:1/C14:0 and C16:1/C16:0 (p < 0.05, p < 0.01).

Factors affecting levels of volatile 4-alkyl branched-chain fatty acids in sheep milk from 2 contrasting farming systems in New Zealand

Knowledge of factors influencing the levels of 4-alkyl branched-chain fatty acid (vBCFA), and consequently the "sheepy flavor" intensity of New Zealand sheep milk, is currently limited. In this study, we investigated the effects of 2 contrasting farming systems (fully housed/mid-lactation or pasture-grazed/late lactation) on the levels of vBCFA in sheep milk on a commercial farm in the North Island of New Zealand. Fully housed/mid-lactation ewes were housed 24 h/d and fed a total mixed ration. Pasture-grazed/late-lactation ewes were grazed 24 h/d and offered approximately 40% supplements because of poor pasture growth resulting from dry and hot climatic conditions. Any effects of genetics, age, lactation stage, feed composition, lambing date, or the environment in the housing barn or outdoors were confounded. The results obtained in this study were descriptive rather than definitive, because of the limitations of the experimental design. Levels of 4-methyloctanoic acid and 4-methylnonanoic acid in milk from fully housed/mid-lactation ewes increased during the trial period, but remained low in milk from pasture-grazed/late-lactation ewes. Levels of 4-ethyloctanoic acid in milk from the 2 groups of ewes were comparable throughout the trial. Increases in levels of 4-methyloctanoic acid and 4-methylnonanoic acid in sheep milk were associated with lactation stage and the proportion of lucerne silage fed to ewes. The level of free-form 4-ethyloctanoic acid was positively correlated with the proportion of soy meal in the diet and negatively correlated with the proportion of barley. Milk from fully housed/mid-lactation ewes had a higher flavor values than milk from pasture-grazed/late-lactation ewes because of its higher total amounts of vBCFA.