Casein hydrolysates (CH) were prepared using papain and modified by the plastein reaction (CH-P) in the presence of extrinsic phenylalanine (CH-P-Phe) or tryptophan (CH-P-Trp). The in vitro protective activity of CH and its modified products against ethanol-induced damage in HHL-5 cells was investigated. The results showed that the modification by the plastein reaction reduced the amino group content of CH. However, the modification by the plastein reaction in the presence of extrinsic amino acids could enhance the antioxidant, proliferative, cell cycle arresting, and anti-apoptosis activity of CH. Biological activities of CH and its modified products in the HHL-5 cells varied depending on the hydrolysate concentration (1, 2, and 3 mg/mL) and treatment time (24, 48, and 72 h). Generally, higher biological activities were found after cell treatment with CH or its modified products at concentration of 2 mg/mL for 48 h compared to other treatments. In addition, CH modified in the presence of tryptophan (CH-P-Trp) showed higher biological activity than that modified in the presence of phenylalanine (CH-P-Phe). Based on the obtained results, it can be concluded that casein hydrolysates with enhanced biological activity and potential health benefits can be produced by papain and the plastein reaction with the incorporation of extrinsic amino acids.

Lactoferrin is an interesting bioactive protein in milk and can interact with various metal ions of trace elements such as copper, iron, manganese, and others. In this study, a lactoferrin hydrolysate (LFH) was generated from commercial bovine lactoferrin by protease pepsin, fortified with Cu²⁺ (or Mn²⁺) at two levels of 0.64 and 1.28 (or 0.28 and 0.56) mg/g protein, respectively, and then measured for the resultant bioactivity changes in the well-differentiated human gastric cancer AGS cells. The assaying results indicated that the LFH and Cu/Mn-fortified products had long-term anti-proliferation on the cells, while the treated cells showed DNA fragmentation and increased apoptotic cell proportions. Regarding the control cells, the cells treated with the LFH and especially Cu/Mn-fortified LFH had remarkably up-regulated mRNA expression of caspase-3 and Bax by respective 1.21–3.23 and 2.23–2.83 folds, together with down-regulated mRNA expression Bcl-2 by 0.88–0.96 folds. Moreover, Western-blot assaying results also indicated that the cells exposed to the LFH and Cu/Mn-fortified LFH (especially Mn at higher level) for 24 h had an enhanced caspase-3 expression and increased ratio of Bax/Bcl-2. It can thus be concluded that the used Cu/Mn-addition to the LFH may lead to increased bioactivity in the AGS cells; to be more specific, the two metal ions at the used addition levels could endow LFH with a higher ability to cause cell apoptosis by activating caspase-3 and increasing the Bax/Bcl-2 ratio.

In the present study, carrot juice prepared was added into skimmed milk before fermentation to produce 10% and 20% (w/w) carrot-fortified skim milk. The influence of carrot juice on the lactic acid content, chemical composition, syneresis, texture, rheology property, and microstructure was evaluated along with a potential of carrot juice as an ingredient with rich dietary fiber and a firm structure with interaction of milk protein and a complex matrix under acidification. The results showed that the pH of yoghurt significantly ( ) reduced with carrot juice addition, minimizing fermentation time by nearly 1 h and brought about an enhanced postacidification during the storage period while titratable acidity increased. Moreover, carrot juice addition had no significant effect on ferric reducing power and phenolic content ( ). With 10% and 20% level carrot juice added, the total phenolic content (mg GAEkg⁻¹) increased (37.86 and 38.92, respectively) compared with control (36.91) ( ). Besides, the addition of carrot juice also showed reduced syneresis, increased apparent viscosity and viscoelastic modulus, stable texture, and a refined microstructure. Overall, this study confirmed that carrot juice has a potential as natural and nutrient composition to obtain firm and compact texture and enhance the beneficial quality of yoghurt.

Corn glutelin hydrolysate (CGH) was prepared by alkaline protease hydrolysis of corn glutelin and further modified by histidine (His) and tryptophan (Trp) through the Plastein reaction, obtaining His-fortified CGH (His-CGH) and Trp-fortified CGH (Trp-CGH). The functional properties (solubility, foaming capacity, and emulsifying activity) of the modified peptides were analyzed. The corresponding modifiers were added to baked products to evaluate potential application in the baking field. The effects of the modifiers on batter density, specific volume, and textural properties of chiffon cake were investigated. This study aimed to enhance the functional characteristics of corn glutelin and provide a theoretical basis for the development of functional products or green food additives. Corn glutelin hydrolysate supplemented with His-CGH and Trp-CGH exhibited improved solubility, foaming stability, and emulsifying capacity. Compared with CGH, the foamability (FC) of Trp-CGH increased by 9%, the foaming stability (FS10) at 10 min elevated by 8.41%, the foaming stability (FS20) at 20 min improved by 14.79%, and the foaming stability at 30 min (FS30) raised by 14.14%. The emulsifying activity of Trp-CGH improved by 10.65 m²/g, and the emulsifying stability increased by 10.57 min. Furthermore, the batter density of the cake sample with Trp-CGH decreased by 0.028 g/cm³, the specific volume increased by 0.29 cm³/g, the baking loss rate lowered by 0.99%, and the hardness reduced by 0.36 N. The improvement of these quality indexes remarkably enhanced the sensory acceptance and texture of the cake sample. Overall, it also reveals that the addition of the Plastein reaction modifiers before baking also highlights their potential as green food additives in baking products.

This study investigated the effects of various concentrations of coriander seed powder (CSP) (0.1%, 0.3%, and 0.5%) on the fermentation performance, whey precipitation rate, texture, rheological properties, microstructure, and sensory characteristics of spoonable yoghurt stored at 4 °C for 21 days. The aim was to evaluate the impact of CSP on spoonable yoghurt quality and its health-promoting properties. The results revealed that the addition of CSP led to a significant decrease in pH and an increase in titratable acidity. Furthermore, the whey precipitation rate in the CSP-enriched yogurt sample was clearly lower than that of the control group (p < 0.05). The syneresis of the yogurt sample with 0.3% CSP decreased by 21.14 on the 21st day, compared to the control group (49.64%) (p < 0.05). This was accompanied by a reduction in apparent viscosity and an increase in the viscoelastic modulus. Meanwhile, the texture of the yogurt sample remains more stable, with the best sensory acceptance in the yogurt sample containing 0.3% CSP. As the concentration of coriander seed powder level increased, antioxidant activity, digestibility, and small molecule phenolic level of the yogurt samples obviously improved (p < 0.05). Yogurt with 0.3% CSP still showed significantly enhanced antioxidant capacity during the 21-day storage period. The DPPH-radical scavenging rate increased by 5.22% compared to the control group (p < 0.05). Similarly, the ABTS+ clearance activity increased by 12.52% (47.06% compared to 34.54% in the control group, p < 0.05). In the 0.3% CSP yogurt group, the total phenolic content reached 5.33 mg GAE/100 g, an increase of 1.85 compared to the control sample (3.48 mg GAE/100 g) (p < 0.05). The in vitro protein digestibility of the yogurt samples containing 0.3% CSP clearly increased by 12.65% (p < 0.05). In summary, the yogurt sample supplemented with 0.3% CSP demonstrated optimal sensory quality characteristics. Coriander seed powder may be used as a beneficial ingredient containing rich active substances to enhance the quality of spoonable yoghurt products.