Dynamic in vitro gastric digestion behavior of goat milk: Effects of homogenization and heat treatments

The aim of the present study was to assess the effects of different flow-through heat treatments—68, 73, 78, 85, 100 °C for 16 s—applied to in-line homogenized goat and sheep milk. Alkaline phosphatase (ALP) activity in raw goat milk was 324.5 ± 47.3 μg phenol/mL, and that of lactoperoxidase (LPO) was 199.3 ± 6.7 U/L. The respective activities in raw sheep milk were 7615 ± 141 μg phenol/mL and 319 ± 38.6 U/L. LPO activity was not detected in both milk kinds treated at 85 °C for 16 s. Residual enzyme activities at 73 °C for 16 s with respect to the initial levels in raw milk were higher in goat than in sheep milk. The whey protein fraction of sheep milk was more heat sensitive compared to goat counterpart. Sheep milk rennet clotting time (RCT) was not affected by the treatments, while curd firmness decreased significantly (p < 0.05) at 100 °C for 16 s. Treatments more intense than 73 °C for 16 s increased the RCT of goat milk significantly but inconsistently and decreased curd firmness significantly, while yoghurt-type gels made from 73 °C or 78 °C for 16 s treated goat milk exhibited the highest water-holding capacity.

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Effect of reducing sugars on the in-vitro glycation of goat milk whey protein by mass spectrometry

LWT ◽

10.1016/j.lwt.2021.111608 ◽

2021 ◽

pp. 111608

Author(s):

Lina Zhang ◽

Manik Chandra Roy ◽

Peng Zhou

Keyword(s):

Mass Spectrometry ◽

Whey Protein ◽

Reducing Sugars ◽

Goat Milk ◽

Milk Whey ◽

Milk Whey Protein

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Impact of the Simulated Gastric Digestion Methodology on the In Vitro Intestinal Proteolysis and Lipolysis of Emulsion Gels

Foods ◽

10.3390/foods10020321 ◽

2021 ◽

Vol 10 (2) ◽

pp. 321

Author(s):

Camila Mella ◽

Michelle Quilaqueo ◽

Rommy N. Zúñiga ◽

Elizabeth Troncoso

Keyword(s):

Heat Treatment ◽

Protein Isolate ◽

Gastric Digestion ◽

Human Gastrointestinal Tract ◽

Gel Structure ◽

Intestinal Digestion ◽

Food Digestion ◽

The Impact ◽

Digestion Methods

The aim of this work was to study the impact of the methodology of in vitro gastric digestion (i.e., in terms of motility exerted and presence of gastric emptying) and gel structure on the degree of intestinal proteolysis and lipolysis of emulsion gels stabilized by whey protein isolate. Emulsions were prepared at pH 4.0 and 7.0 using two homogenization pressures (500 and 1000 bar) and then the emulsions were gelled by heat treatment. These gels were characterized in terms of texture analysis, and then were subjected to one of the following gastric digestion methods: in vitro mechanical gastric system (IMGS) or in vitro gastric digestion in a stirred beaker (SBg). After gastric digestion, the samples were subjected to in vitro intestinal digestion in a stirred beaker (SBi). Hardness, cohesiveness, and chewiness were significantly higher in gels at pH 7.0. The degree of proteolysis was higher in samples digested by IMGS–SBi (7–21%) than SBg–SBi (3–5%), regardless of the gel’s pH. For SBg–SBi, the degree of proteolysis was not affected by pH, but when operating the IMGS, higher hydrolysis values were obtained for gels at pH 7.0 (15–21%) than pH 4.0 (7–13%). Additionally, the percentage of free fatty acids (%FFA) released was reduced by 47.9% in samples digested in the IMGS–SBi. For the methodology SBg–SBi, the %FFA was not affected by the pH, but in the IMGS, higher values were obtained for gels at pH 4.0 (28–30%) than pH 7.0 (15–19%). Our findings demonstrate the importance of choosing representative methods to simulate food digestion in the human gastrointestinal tract and their subsequent impact on nutrient bioaccessibility.

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In vitro dynamic gastric digestion of soya protein/milk protein blended beverages: influence of protein composition and co-processing

Food & Function ◽

10.1039/d0fo02742a ◽

2021 ◽

Vol 12 (6) ◽

pp. 2605-2616

Author(s):

Teresa Francis Wegrzyn ◽

Alejandra Acevedo-Fani ◽

Simon M. Loveday ◽

Harjinder Singh

Keyword(s):

Whey Protein ◽

Milk Protein ◽

Protein Composition ◽

Soya Protein ◽

Gastric Digestion ◽

Heat Treated ◽

Protein Milk

The gastric digestion behaviours of blended protein beverages containing different ratios of casein, whey protein and soya protein that were heat-treated at 60 °C or 80 °C were investigated using an in vitro dynamic human gastric simulator.

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Optimization of a functional food product based on fibers and proteins: Rheological, textural, sensory properties, and in vitro gastric digestion related to enhanced satiating capacity

LWT ◽

10.1016/j.lwt.2021.111586 ◽

2021 ◽

Vol 147 ◽

pp. 111586

Author(s):

Fardin Javanmardi ◽

Kooshan Nayebzadeh ◽

Atoosa Saidpour ◽

Meisam Barati ◽

Amir Mohammad Mortazavian

Keyword(s):

Functional Food ◽

Food Product ◽

Sensory Properties ◽

Gastric Digestion

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Gastric secretion rate and protein concentration impact intragastric pH and protein hydrolysis during dynamic in vitro gastric digestion

Food Hydrocolloids for Health ◽

10.1016/j.fhfh.2021.100027 ◽

2021 ◽

Vol 1 ◽

pp. 100027

Author(s):

Yamile A. Mennah-Govela ◽

Clay Swackhamer ◽

Gail M. Bornhorst

Keyword(s):

Gastric Secretion ◽

Protein Concentration ◽

Secretion Rate ◽

Protein Hydrolysis ◽

Intragastric Ph ◽

Gastric Digestion

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In vitro gastrointestinal digestion of pea protein isolate as a function of pH, food matrices, autoclaving, high-pressure and re-heat treatments

LWT ◽

10.1016/j.lwt.2017.06.021 ◽

2017 ◽

Vol 84 ◽

pp. 511-519 ◽

Cited By ~ 20

Author(s):

Laura Laguna ◽

Pierre Picouet ◽

M. Dolors Guàrdia ◽

Catherine M.G.C. Renard ◽

Anwesha Sarkar

Keyword(s):

High Pressure ◽

Protein Isolate ◽

Heat Treatments ◽

Gastrointestinal Digestion ◽

Pea Protein ◽

In Vitro Gastrointestinal Digestion ◽

Food Matrices ◽

Pea Protein Isolate

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Extent of damage to amino acid availability of whey protein heated with sugar

Journal of Dairy Research ◽

10.1017/s002202990003003x ◽

1991 ◽

Vol 58 (4) ◽

pp. 431-441 ◽

Cited By ~ 13

Author(s):

Thérèse Desrosiers ◽

Laurent Savoie

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Whey Protein ◽

Significant Proportion ◽

Protein Digestibility ◽

Heating Time ◽

Heat Treatments ◽

Molar Ratio ◽

Amino Acid Availability

SummaryThe effect of heat treatments, at various water activities (αw), on digestibility and on the availabilities of amino acids of whey protein samples in the presence of lactose was estimated by an in vitro digestion method with continuons dialysis. Four αw (0·3, 0·5, 0·7 and 0·97), three temperatures (75, 100 and 121 °C) and three heating periods (50, 500 and 5000 s) were selected. The initial lysine: lactose molar ratio was 1:1. Amino acid profiles showed that excessive heating of whey (121 °C, 5000 s) destroyed a significant proportion of cystine at all αw, lysine at αw 0·3, 0·5 and 0·7, and arginine at αw 0·5 and 0·7. At αw 0·3, 0·5 and 0·7, protein digestibility decreased (P < 0·05) as the temperature increased from 75 to 121 °C for a heating period of 5000 s, and as the heating time was prolonged from 500 to 5000 s at 121 °C. Excessive heating also decreased (P < 0·05) the availabilities of ail amino acids at αw 0·3, 0·5 and 0·7. The availabilities of lysine, proline, aspartic acid, glutamic acid, threonine, alanine, glycine and serine were particularly affected. Severe heating at αw 0·97 did not seem to favour the Maillard reaction, but the availabilities of cystine, tyrosine and arginine were decreased, probably as a result of structural modifications of the protein upon heating. Heating whey protein concentrates in the presence of lactose not only affected lysine, but also impaired enzymic liberation of other amino acids, according to the severity of heat treatments and αw.

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