Cultured milk (fermented milk)

Description
• Dairy product obtained from milk (fresh or reconstituted/standardized) fermented with selected starter cultures (e.g., Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus; kefir also includes yeasts).
• Fermentation converts part of lactose to lactic acid, lowering pH and coagulating casein micelles; the result ranges from pourable beverages to spoonable gels.
• Products may contain live cultures through end of shelf-life, or be post-pasteurized (no live cultures).

Caloric value (per 100 g of product)
• Whole “plain” (no added sugars): ~60–70 kcal; protein ~3.3–4.0 g; carbohydrates (residual lactose) ~3.5–5.0 g; fat ~3.0–3.8 g.
• Semi-skimmed: ~45–55 kcal; protein ~3.5–4.0 g; fat ~1.5–2.0 g.
• Skim/0–0.1% fat: ~35–45 kcal; protein ~3.8–4.5 g; fat ≤0.2 g.
• Fat profile (whole product): SFA (saturated fatty acids; moderate intake advised) ~2–2.5 g; MUFA (monounsaturated; generally favorable/neutral for lipids) ~0.8–1.2 g; PUFA (polyunsaturated; includes n-6/n-3) ~0.1–0.2 g; small fraction of MCT (medium-chain triglycerides; rapidly absorbed).

Key constituents
• Proteins: caseins and whey proteins; fermentation-derived peptides.
• Carbohydrates: reduced lactose vs milk; galactose; sugars added in sweetened products.
• Lipids: triglycerides with phospholipids; SFA predominant; MUFA/PUFA minor.
• Acid and metabolites: lactic acid, EPS (exopolysaccharides), flavor compounds (acetaldehyde, diacetyl, etc.).
• Vitamins: B2, B12, A (in whole products), variable K2; minerals: calcium, phosphorus, potassium.
• Live cultures (if present): typical end-of-life levels ≥10⁷–10⁸ CFU/g.

Production process
• Raw materials: standardized milk (fat/protein), homogenized and heat-treated (thermized/pasteurized).
• Inoculation: add starter—thermophilic (e.g., yogurt) or mesophilic (e.g., filmjölk); kefir uses symbiotic grains.
• Fermentation: 30–45 °C for thermophiles / 20–30 °C for mesophiles to pH ~4.2–4.6; 2–16 h depending on style.
• Cooling and aseptic filling; optional fruit/flavors/stabilizers; maintain cold chain.
• Controls: pH/titratable acidity, viscosity/syneresis, CFU, safety microbiology, full traceability under GMP/HACCP.

Sensory and technological properties
• Acidity and fresh lactic aroma; texture from drinkable to spoonable (governed by EPS and process).
• Functionality: texture building, acidification, mild tenderizing in marinades; humectant behavior in sauces/batters.
• Compatibility: instability at high pH or with strong salts/acids; risk of syneresis without adequate process/stabilizers.

Food uses
• Direct consumption (drinkable or set), breakfast bowls, smoothies, desserts.
• Culinary: light acidic dressings, marinades, baking, ice cream/semifreddo.
• Functional formats: high-protein, lactose-free, fiber-enriched or n-3-enriched versions.

Nutrition and health
• Digestibility: reduced lactose → better tolerance for some hypolactasia subjects (not universally sufficient).
• Protein quality: high; fermentation may yield bioactive peptides (e.g., potential ACE-inhibitory activity—limited in-vivo evidence).
• Fats: predominance of SFA (moderation advised), presence of MUFA/PUFA; n-3 modest unless enriched.
• Microbiota: products with live cultures may deliver probiotics/postbiotics; health claims must follow regulations.
• Minerals/vitamins: good calcium and B12 sources; sodium generally low.

Quality and specifications (typical topics)
• Final pH 4.2–4.6; titratable acidity; declared species’ CFU profile.
• Absence of pathogens; coliforms/yeasts/molds within spec.
• Stability: viscosity, syneresis, phase separation; pack integrity; validated shelf-life.
• Clear labeling of live cultures, added sugars, flavors, and allergens.

Storage and shelf-life
• Keep at 0–4 °C, protected from light/thermal shocks; never break the cold chain.
• Typical shelf-life 2–6 weeks depending on process/pack; once opened, consume within 2–5 days.
• Avoid freezing (texture instability).

Allergens and safety
• Contains milk and derivatives (major allergen).
• Not suitable for cow’s-milk protein allergy; caution for lactose intolerance unless clearly “lactose-free.”
• Raw materials and plants under GMP/HACCP; avoid raw-milk fermented products for vulnerable groups.

INCI functions in cosmetics
• Typical entries: Lactobacillus Ferment, Milk Ferment Filtrate, Yogurt Powder.
• Roles: skin conditioning, soothing, postbiotic/microbiome balance, mild humectancy; common in masks and gentle leave-ons.

Troubleshooting
• Excess syneresis: over-acidification/weak gel → optimize starter, EPS, homogenization/stabilizers.
• Over-acidification/post-acidification: high inoculum or cold-chain issues → reduce inoculum, improve refrigeration.
• Gas/swelling: heterofermenters or yeasts → hygiene, milk thermization, air filtration/bacteriostasis.
• Off-flavor (bitter/yeasty): milk quality/oxidation → monitor TBARS, use barrier packs, enforce FIFO.

Sustainability and supply chain
• Effluent management with attention to BOD/COD; valorize whey and by-products.
• Recyclable packaging (PET/HDPE/carton) and optimized cold logistics.
• Efficient cultures and waste reduction to lower environmental footprint.

Conclusion
Cultured milk delivers high-quality proteins, improved tolerance relative to milk, fresh sensory appeal, and broad technological versatility. Final quality depends on milk, starter selection, control of pH/CFU, and a robust cold chain; transparent labeling and processes under GMP/HACCP ensure safety and consistency.

Mini-glossary
• SFA — Saturated fatty acids: limit excessive intake; can raise LDL cholesterol.
• MUFA — Monounsaturated fatty acids (e.g., oleic): generally favorable/neutral for blood lipids.
• PUFA — Polyunsaturated fatty acids: include n-6 and n-3; beneficial when balanced.
• n-6 — Omega-6 fatty acids: essential; excess vs n-3 may promote pro-inflammatory balance.
• n-3 — Omega-3 fatty acids: supportive for cardiovascular and neural health.
• ALA — Alpha-linolenic acid (n-3): precursor to EPA/DHA; limited conversion in adults.
• EPA — Eicosapentaenoic acid (n-3): cardiovascular and anti-inflammatory support.
• DHA — Docosahexaenoic acid (n-3): structural for brain and retina.
• TFA — Trans fatty acids: natural traces in dairy; industrial TFAs should be avoided.
• MCT — Medium-chain triglycerides: rapidly absorbed fats present in small amounts in milk fat.
• CFU — Colony forming units: measure of viable microorganisms.
• EPS — Exopolysaccharides: microbial polysaccharides that improve viscosity/stability.
• pH — Acidity/alkalinity index; key for gelation and shelf-life.
• GMP — Good Manufacturing Practice: hygiene and process consistency standards.
• HACCP — Hazard Analysis and Critical Control Points: preventive safety system with defined CCP.
• CCP — Critical Control Point: step where a control prevents/eliminates/reduces a hazard.
• BOD/COD — Biochemical/Chemical Oxygen Demand: effluent impact indicators on water quality.
• FIFO — First In, First Out: stock rotation strategy using older lots first.
• LDL — Low-density lipoprotein cholesterol: high levels increase CVD risk.

References__________________________________________________________________________

Rizzoli R, Biver E. Effects of Fermented Milk Products on Bone. Calcif Tissue Int. 2018 Apr;102(4):489-500. doi: 10.1007/s00223-017-0317-9. 

Abstract. Fermented milk products like yogurt or soft cheese provide calcium, phosphorus, and protein. All these nutrients influence bone growth and bone loss. In addition, fermented milk products may contain prebiotics like inulin which may be added to yogurt, and provide probiotics which are capable of modifying intestinal calcium absorption and/or bone metabolism. On the other hand, yogurt consumption may ensure a more regular ingestion of milk products and higher compliance, because of various flavors and sweetness. Bone mass accrual, bone homeostasis, and attenuation of sex hormone deficiency-induced bone loss seem to benefit from calcium, protein, pre-, or probiotics ingestion, which may modify gut microbiota composition and metabolism. Fermented milk products might also represent a marker of lifestyle promoting healthy bone health.

Branca F, Rossi L. The role of fermented milk in complementary feeding of young children: lessons from transition countries. Eur J Clin Nutr. 2002 Dec;56 Suppl 4:S16-20. doi: 10.1038/sj.ejcn.1601676.

Abstract. Probiotic bacteria are used for production of fermented dairy products. The use of probiotic bacteria has the potential to replenish the natural intestinal flora of the body. These bacteria competitively inhibit the growth and colonization of pathogenic bacteria. Breastmilk is the best food for babies, also from a probiotic point of view. Human milk, in fact, contains many substances that stimulate the growth of bifidobacteria in vitro and in the small intestine of infants. Improvement of lactose digestion and avoidance of symptoms of intolerance in lactose malabsorbers are the most profoundly studied health-relevant effects of fermented milk. In fact fermented milks are nutritionally similar to unfermented milk, except that some of lactose is broken down to glucose and galactose. The role of fermented milk in complementary feeding and in particular for the prevention of anaemia is an innovative theme, recently focused. Iron deficiency in infants and young children is widespread and has serious consequences for child health. Prevention of iron deficiency should therefore be given high priority. The too-early introduction of unmodified cow's milk and milk products is an important nutritional risk factors for the development of iron-deficiency anaemia. Fermented milks represent an excellent source of nutrients such as calcium, protein, phosphorus and riboflavin. During the fermentation of milk, lactic acid and other organic acids are produced and these increase the absorption of iron. If fermented milk is consumed at mealtimes, these acids are likely to have a positive effect on the absorption of iron from other foods.

Chen L, Bagnicka E, Chen H, Shu G. Health potential of fermented goat dairy products: composition comparison with fermented cow milk, probiotics selection, health benefits and mechanisms. Food Funct. 2023 Apr 24;14(8):3423-3436. doi: 10.1039/d3fo00413a. 

Abstract. Goat milk as a preferable probiotic vehicle has been investigated and the contribution of fermented goat dairy products to the nutritional and economic wellbeing of the world is tremendous. This review presents the recent progress on fermented goat dairy products, including probiotic selection, composition comparison to fermented cow milk, health effects, and related mechanisms. Fermented goat milk maintains a better nutritional profile in comparison to fermented cow milk with higher values of protein, minerals (Ca, Mg, Fe, Cu, Zn and Se), vitamins (A, D3 and B12) and some fatty acids. Lactobacillus is the predominant genus used in goat milk fermentation and endows goat milk with higher functional value, including gut microbiota regulation, anti-microbial and anti-inflammatory functions, hypocholesterolemic effects, antioxidant effects, hypotensive effects, bone health, anemia recovery, anti-obesity, and anti-atherogenic function. The corresponding mechanisms have been elucidated at the molecular level. A series of collection on probiotics starters, fermentation strategy and characteristics of fermented goat dairy products are performed. Although the industrial applications of fermented goat milk remain underdeveloped, the improved functional annotation and fermentation strategy identified in this review provide a bright future and an excellent framework for the future fermented goat dairy market.

Ebringer L, Ferencík M, Krajcovic J. Beneficial health effects of milk and fermented dairy products--review. Folia Microbiol (Praha). 2008;53(5):378-94. doi: 10.1007/s12223-008-0059-1.

Abstract. Milk is a complex physiological liquid that simultaneously provides nutrients and bioactive components that facilitate the successful postnatal adaptation of the newborn infant by stimulating cellular growth and digestive maturation, the establishment of symbiotic microflora, and the development of gut-associated lymphoid tissues. The number, the potency, and the importance of bioactive compounds in milk and especially in fermented milk products are probably greater than previously thought. They include certain vitamins, specific proteins, bioactive peptides, oligosaccharides, organic (including fatty) acids. Some of them are normal milk components, others emerge during digestive or fermentation processes. Fermented dairy products and probiotic bacteria decrease the absorption of cholesterol. Whey proteins, medium-chain fatty acids and in particular calcium and other minerals may contribute to the beneficial effect of dairy food on body fat and body mass. There has been growing evidence of the role that dairy proteins play in the regulation of satiety, food intake and obesity-related metabolic disorders. Milk proteins, peptides, probiotic lactic acid bacteria, calcium and other minerals can significantly reduce blood pressure. Milk fat contains a number of components having functional properties. Sphingolipids and their active metabolites may exert antimicrobial effects either directly or upon digestion.

Usinger L, Reimer C, Ibsen H. Fermented milk for hypertension. Cochrane Database Syst Rev. 2012 Apr 18;2012(4):CD008118. doi: 10.1002/14651858.CD008118.pub2. 

Abstract. Background: Fermented milk has been suggested to have a blood pressure lowering effect through increased content of proteins and peptides produced during the bacterial fermentation. Hypertension is one of the major risk factors for cardiovascular disease world wide and new blood pressure reducing lifestyle interventions, such as fermented milk, would be of great importance. Objectives: To investigate whether fermented milk or similar products produced by lactobacilli fermentation of milk proteins has any blood pressure lowering effect in humans when compared to no treatment or placebo. Search methods: The Cochrane Central Register of Controlled Trials (CENTRAL), English language databases, including MEDLINE (1966-2011), EMBASE (1974-2011), Cochrane Complementary Medicine Trials Register, Allied and Complementary Medicine (AMED) (1985-2011), Food science and technology abstracts (1969-2011). Selection criteria: Randomised controlled trials; cross over and parallel studies evaluating the effect on blood pressure of fermented milk in humans with an intervention period of 4 weeks or longer. Data collection and analysis: Data was extracted individually by two authors, afterwards agreement had to be obtained before imputation in the review. Main results: A modest overall effect of fermented milk on SBP was found (MD -2.45; 95% CI -4.30 to -0.60), no effect was evident on DBP (MD -0.67; 95% CI -1.48, 0.14).

Ohsawa K, Uchida N, Ohki K, Nakamura Y, Yokogoshi H. Lactobacillus helveticus-fermented milk improves learning and memory in mice. Nutr Neurosci. 2015 Jul;18(5):232-40. doi: 10.1179/1476830514Y.0000000122. 

Abstract. Objectives: To investigate the effects of Calpis sour milk whey, a Lactobacillus helveticus-fermented milk product, on learning and memory. Methods: We evaluated improvement in scopolamine-induced memory impairment using the spontaneous alternation behaviour test, a measure of short-term memory. We also evaluated learning and working memory in mice using the novel object recognition test, which does not involve primary reinforcement (food or electric shocks). A total of 195 male ddY mice were used in the spontaneous alternation behaviour test and 60 in the novel object recognition test. Results: Forced orally administered Calpis sour milk whey powder (200 and 2000 mg/kg) significantly improved scopolamine-induced cognitive impairments (P < 0.05 and P < 0.01, respectively) and object recognition memory (2000 mg/kg; P < 0.05). Discussion: These results suggest that Calpis sour milk whey may be useful for the prevention of neurodegenerative disorders, such as Alzheimer's disease, and enhancing learning and memory in healthy human subjects; however, human clinical studies are necessary.

Mathur H, Beresford TP, Cotter PD. Health Benefits of Lactic Acid Bacteria (LAB) Fermentates. Nutrients. 2020 Jun 4;12(6):1679. doi: 10.3390/nu12061679. 

Abstract. Consuming fermented foods has been reported to result in improvements in a range of health parameters. These positive effects can be exerted by a combination of the live microorganisms that the fermented foods contain, as well as the bioactive components released into the foods as by-products of the fermentation process. In many instances, and particularly in dairy fermented foods, the microorganisms involved in the fermentation process belong to the lactic acid group of bacteria (LAB). An alternative approach to making some of the health benefits that have been attributed to fermented foods available is through the production of 'fermentates'. The term 'fermentate' generally relates to a powdered preparation, derived from a fermented product and which can contain the fermenting microorganisms, components of these microorganisms, culture supernatants, fermented substrates, and a range of metabolites and bioactive components with potential health benefits. Here, we provide a brief overview of a selection of in vitro and in vivo studies and patents exclusively reporting the health benefits of LAB 'fermentates'. Typically, in such studies, the potential health benefits have been attributed to the bioactive metabolites present in the crude fermentates and/or culture supernatants rather than the direct effects of the LAB strain(s) involved.

Maruta H, Fujii Y, Toyokawa N, Nakamura S, Yamashita H. Effects of Bifidobacterium-Fermented Milk on Obesity: Improved Lipid Metabolism through Suppression of Lipogenesis and Enhanced Muscle Metabolism. Int J Mol Sci. 2024 Sep 14;25(18):9934. doi: 10.3390/ijms25189934. 

Abstract. Obesity is a major global health concern. Studies suggest that the gut microflora may play a role in protecting against obesity. Probiotics, including lactic acid bacteria and Bifidobacterium, have garnered attention for their potential in obesity prevention. However, the effects of Bifidobacterium-fermented products on obesity have not been thoroughly elucidated. Bifidobacterium, which exists in the gut of animals, is known to enhance lipid metabolism. During fermentation, it produces acetic acid, which has been reported to improve glucose tolerance and insulin resistance, and exhibit anti-obesity and anti-diabetic effects. Functional foods have been very popular around the world, and fermented milk is a good candidate for enrichment with probiotics. In this study, we aim to evaluate the beneficial effects of milks fermented with Bifidobacterium strains on energy metabolism and obesity prevention. Three Bifidobacterium strains (Bif-15, Bif-30, and Bif-39), isolated from newborn human feces, were assessed for their acetic acid production and viability in milk. These strains were used to ferment milk. Otsuka-Long-Evans Tokushima Fatty (OLETF) rats administered Bif-15-fermented milk showed significantly lower weight gain compared to those in the water group. The phosphorylation of AMPK was increased and the expression of lipogenic genes was suppressed in the liver of rats given Bif-15-fermented milk. Additionally, gene expression related to respiratory metabolism was significantly increased in the soleus muscle of rats given Bif-15-fermented milk. These findings suggest that milk fermented with the Bifidobacterium strain Bif-15 can improve lipid metabolism and suppress obesity.