Evaluation of processing methods and oral mastication on the carotenoid bioaccessibility of restructured carrot chips

Effect of cold plasma synergistic acid induction on the quality characteristics of casein gel

Dielectric barrier discharge cold plasma (DBD-CP) technology was used to modify casein acid-gel. The effect of DBD-CP on gel was evaluated in terms of gel quality, texture, antibacterial activity and structure. The results showed that the water holding capacity (WHC) and electrical conductivity of the gel were significantly increased after DBD-CP treatment, and WHC was increased from 66.97 % to 90.68 % (p < 0.05). The springiness of the gel is low frequency dependent, the α-helix decreases (22.12-14.01 %), the β-angle increases (19.98-32.16 %), and hydrophobic and disulfide bonds become the main chemical forces. WHC is positively correlated with conductivity and hardness, and negatively correlated with springiness. DBD-CP promoted protein aggregation and modified the properties of acid-gel, and the gel quality of indirect processing (IP) group was better than that of direct processing (DP) group. The best casein acid-gel was obtained under the conditions of 50 V for 60 s.

Effect of heat and pulsed electric field treatment on the physicochemical and nutritional properties of carrots

BACKGROUND

Carrots are widely used in home cooking and vegetable processing industries because of their high nutritional value. However, different processing methods may produce a negative impact on carrot texture and nutrition quality. Therefore, the development of better processing methods to preserve the texture and nutrition quality of carrots will be beneficial to the carrot industry.

RESULTS

The effects of heat and pulsed electric field (PEF) treatments with different heat temperatures (T) and holding time (t_h ) on comprehensive changes in thermal efficiency profiles, and physicochemical (color, hardness, cell structural damage) and nutritional (releasable β-carotene contents) properties of carrots were studied. In addition, electrical conductivity (σ) and soluble matter contents (°Brix) were determined for the heat-treated extracts. The value of total color difference (∆E) and cell structural damage index (Z) of carrots, σ and °Brix of extracts all increased with increasing T and t_h under different heat experimental conditions, whereas the value of cutting force (F) presented an opposite tendency and content of releasable β-carotene decreased after t_h  > 2 min at T = 100 °C.

CONCLUSION

The results show that PEF heating is beneficial in preventing changes in physicochemical and nutritional properties of carrots compared to traditional heat treatment. PEF has potential as a heating technology in the food industry. © 2022 Society of Chemical Industry.

Bioaccessibility and intestinal cell uptake of carotenoids and chlorophylls differ in powdered spinach by the ingredient form as measured using in vitro gastrointestinal digestion and anaerobic fecal fermentation models

Insights into food matrix factors impacting bioavailability of bioactive carotenoids and chlorophylls from fruits and vegetable ingredients are essential to understanding their ability to promote health. The stability and bioaccessibility of carotenoids and chlorophylls were assessed from dehydrated, spray-dried, freeze-dried and fresh spinach ingredient forms using in vitro models simulating upper gastrointestinal (GI) digestion and lower GI anaerobic fecal fermentation. Intestinal transport of bioaccessible bioactives from both upper and lower GI compartments was assessed using the Caco-2 human intestinal cell model. Differences in carotenoid and chlorophyll contents were observed between ingredient forms and these influenced bioaccessibility. Lower carotenoid and chlorophyll contents in spray dried spinach resulted in the lowest total bioaccessible content among all spinach treatments (5.8 ± 0.2 μmoles per g DW carotenoid and chlorophyll). The total bioaccessible content was statistically similar between freeze-dried (12.5 ± 0.6 μmoles per g DW), dehydrated (12.5 ± 3.2 μmoles per g DW), and fresh spinach (14.2 ± 1.2 μmoles per g DW). Post anaerobic fermentation, cellular accumulation of carotenoids was higher (17.57-19.52 vs. 5.11-8.56%), while that of chlorophylls was lower (3.05-5.27 vs. 5.25-6.44%), compared to those observed following upper GI digestion. Collectively, these data suggest that spinach forms created by various drying technologies deliver similar levels of bioaccessible spinach bioactives and that the lower GI tract may serve as a site for significant absorption fostered by interactions with gut microbial communities that liberate additional bioactives from the spinach matrix.