Table 2.

Modern techniques employed in the isolation and identification of BC components.

Technique/Component	Study Aim	Subject/Sample	Key Findings	Reference
Isobaric tags for relative and absolute quantitation (iTRAQ)-coupled LC-MS	Proteomic analysis of whey protein in BC, mature milk, and human milk.	Colostrum (0–5 days) collected from Chinese Holsten (n = 30), mature milk (15–6 months), and human milk (n = 60).	iTRAQ-coupled LC-MS is the most advanced, reliable, and precise technique in the proteomic quantification of milk from different origins and lactation.	[64]
Laser-perturbation 2-D correlation Raman spectroscopy	Exploration of laser perturbation 2-D correlation Raman spectroscopy method for the reliable and rapid assessment of the quality of BC-based products.	Colostrum samples in milligrams were loaded in porous chips, followed by the Raman spectral analysis. The excitation wavelength was 785 nm and laser power was 450 nm.	The intended approach is simple, rapid (<5 min), and inexpensive.$$$The correlation coefficient analysis assists in improving the difference in experimental samples and improved spectral resolution.$$$In the future, this approach might be utilized to effectively differentiate milk powder in BC-based products.	[65]
UHPLC-QTOF-MS	Characterize and compare the lipids in mature milk and BC based on ultra-high-performance liquid chromatography–quadrupole time of flight mass spectroscopy (UHPLC-QTOF-MS) lipidomics.	Mature milk and BC.	A total of 335 lipids belonging to 13 subclasses were identified in both mature milk and BC.$$$n = 63 lipids were significantly different in mature milk and BC. Out of 63 significantly different lipids, SDLs (n = 21 SDLs) were found to be higher in BC; the rest (n = 42 SDLs) were found to be in an elevated concentration in mature milk.	[3]
Split trehalase immunoglobulin G assay (STIGA)	Develop a novel method for the estimation of IgG in BC and serum at the farm level.	BC (n = 60), calf serum (n = 83), and purified bovine IgG (12.8 mg/mL) used as standard. This STIGA is based on the enzymatic action of trehalase (TreA), which converts trehalose into glucose which is further detected by glucometer.	STIGA is a single step assay that requires less time as compared to other methods which directly measure IgG and could be a promising method to use for the detection of IgG at the farm level.	[66]
Dye affinity chromatography	Purification of lactoperoxidase (LPO) from whey by employing dye affinity chromatography.	Triazine dye (n = 18) was immobilized on Sepharose 6B, followed by the screening of their activity as possible ligands.	Dye–Sepharose (n = 5) matrix showed more than 90% adsorption of LPO without any pretreatment. The Reactive Red-4 Sepharose matrix can be used in the one-step purification of LPO from bovine whey.$$$The dye affinity chromatography has potential in the purification and recovery of LPO from bovine whey by using different chromatographic support.	[67]
Mixed-mode chromatography	Develop an efficient, cost-effective procedure to isolate pure IgG from colostrum whey with minimal activity loss.	Two modes were used to separate the IgG from colostrum whey. Capto multimodal chromatography material (MNC) and MEP HyperCel matrix were used to capture IgG.	The authors isolated pure IgG (130–150 g) from 3 L of whey in five hours. This mixed-mode chromatography results in the purity of 96.1% IgG. This technique can be used in the future for the pure, stable, and active isolation of IgG from bovine milk and colostrum.	[68]
Transmission infrared (IR) spectroscopy and Brix refractometer	Determine the effectiveness of transmission infrared spectroscopy (IR) and Brix refractometer (optical and digital) in the estimation of colostrum IgG concentration.	Colostrum samples of Holstein cow (n = 258). The concentration of IgG was determined in 255 samples using infrared spectroscopy (IR) and radial immunodiffusion assay (RID). Colostrum samples (n = 240) were analyzed by using a refractometer (optical and digital).	Transmission infrared (IR) spectroscopy is an accurate and rapid method to determine the colostrum quality, i.e., IgG, in lab-based testing where the Brix refractometer (digital and digital) is less effective. Moreover, the study suggests that transmission infrared spectroscopy is effective at the lab scale, while the Brix (digital and digital) can be used to determine the colostrum quality at the farm level.	[21]
Exosomal microRNAs	Identify and compare the exosomal $$$microRNAs in both milk and colostrum.	Dogu Anadolu Kirmizisi and Holstein cows,	A total of 795 miRNAs were expressed and identified differently, out of which 545 were identified as miRNAs, of which 250 were identified as novel miRNAs. These miRNAs regulate milk protein and fat metabolism.	[22]
Neutral and acidic oligosaccharides	Isolation of neutral and acidic oligosaccharides from BC and goat milk for infant formula.	20 mL of BC (0–3 days) after parturition, human milk (n = 20) and goat milk were used for the isolation of oligosaccharides through the modified charcoal column method.	The oligosaccharides from goat milk have more potential in terms of adherence inhibition and safety to be utilized in infant formula.	[23]
N-glycoproteomes	Characterize and compare whey N-glycoproteomes from BC, HC, and mature milk.	A bioinformatics analysis using liquid chromatography (LC)–tandem mass spectrometry. Colostrum and mature milk were collected from Holstein cows (n = 60) and HC (n = 60). Further collected samples were divided into 3 pooled groups (n = 20).	N-Glycoproteomes were different in BC, HC, and mature milk. N-Glycoproteomes (68, 58, and 98) were identified in all milk samples. The composition of N-glycoproteomes is significantly changed with lactation.	[20]