Effect of palm stearin on the physicochemical characterization and capsaicinoid digestion of Sichuan hotpot oil

Potential of beef tallow/palm oil blend as Chongqing hotpot oil from a physicochemical and flavor perspective

Beef tallow is an important raw material in Chongqing hotpot seasoning but raises great concern on health due to the cholesterol issue. Herein, palm oil was expected to replace beef tallow at weight ratios of 2:1, 1:1, and 1:2 without reducing hotpot flavor. The blending of palm oil to beef tallow effectively decreased cholesterol content to 33.20 mg 100 g-1, as well as the level of saturated fatty acids to 50 % in hotpot oil. The fading in brightness and yellowness of oil models occurred owing to heat treatment. The blending oil at 2:1 showed similar hardness, melting and crystallization behaviors to beef tallow, probably due to the similar fat crystal network. The volatile compounds of hotpot seasoning made from the oil were closer to that from neat beef tallow. These findings may provide a new strategy to develop healthier and tastier base oil for the production of Chongqing hotpot seasoning.

Insights into the Volatile Flavor Profiles of Two Types of Beef Tallow via Electronic Nose and Gas Chromatography-Ion Mobility Spectrometry Analysis

In the current study, an electronic nose (E-nose) and gas chromatography-ion mobility spectrometry (GC-IMS) were employed to investigate the volatile flavor compounds (VFCs) of intense flavor beef tallow (L) and ordinary beef tallow (P). The study results indicate that an E-nose combined with an LDA and GC-IMS combined with an OPLS-DA can effectively distinguish between the two types of beef tallow. Compared with ordinary beef tallow, the E-nose sensors of intense flavor beef tallow have stronger response signals to sulfides, terpenes, and nitrogen oxides. A total of 22 compounds contribute to making the flavor of intense flavor beef tallow more typical and richer; in contrast, ethyl acetate was the main aroma-active compound found in the ordinary beef tallow. Sulfur-containing compounds and terpenoids might be the key substances that cause sensory flavor differences between the two types of beef tallow. In conclusion, the results of this study clarify the characteristics and differences of the two types of beef tallow and provide an enhanced understanding of the differences in the flavors of the two types of beef tallow.

Application of Different Animal Fats as Solvents to Extract Carotenoids and Capsaicinoids from Sichuan Chili

Inspired by the proved dissolving power of vegetable oils for non-polar and low-polar natural compounds, animal fats with triglycerides as the major components were investigated as food-grade solvents in this study for the simultaneous extraction of carotenoids and capsaicinoids from Sichuan chili. The dissolving power of lard, beef tallow, chicken fat and basa fish oil in the extraction of er jing tiao chili was firstly compared, where animal oils with worse extraction ratios for carotenoids (0.79 mg/g in average) performed better for the extraction of capsaicinoids (0.65 mg/g in average). Furthermore, the solvent effect of animal fats on the oleo-extracts was evaluated in terms of fatty acid composition, oil quality indexes, crystal polymorphism, melting and crystallization behaviors, where no significant differences were observed between animal fats before and after extraction. The oxidative stability of animal fats could be 1.02- up to 2.73-fold enhanced after extraction and the pungency degree could reach the same spicy level as commercial hotpot oil. In addition, the Hansen solubility parameters of solvents and solutes were predicted for further theoretical miscibility study, which helps to make a better comprehension of the dissolving mechanism behind such oleo-extraction. Overall, animal fats demonstrated their considerable solvent power for extracting carotenoids and capsaicinoids simultaneously from Sichuan chili, which showed significant potential for developing a novel Sichuan spicy hotpot oil with enhanced flavor and stability.

Texture and volatile profiles of beef tallow substitute produced by a pilot-scale continuous enzymatic interesterification

Edible beef tallow (BT) has been widely used in Sichuan hotpot due to its unique flavor and texture. However, BT should not be consumed in excess caused by its trans-fatty acids and cholesterol issues. In this study, a BT substitute was prepared after enzymatic interesterification in a pilot-scale packed-bed reactor using soybean oil and fully hydrogenated palm oil (4:3, w/w) as feedstock. The products were characterized against BT in terms of fatty acid/triacylglycerol compositions, solid fat content, polymorphism, and melting/crystallization behaviors to select the most promising BT substitute. The optimal flow rate was 120 mL/min. Changes in volatile compounds during stir-frying and simmering were also investigated for Sichuan hotpots made with these two oils. The volatile compounds of BT substitute were similar to that of natural BT. The findings will contribute to expanding the base oil categories of Sichuan hotpot oils.

Saltiness enhancement by "má là" umami flavor in NaCl model aqueous and oil-added systems

The health concerns associated with high dietary sodium and the quest for a sensory experience have prompted the need for new strategies that can reduce the salt content of foods and have good acceptability. To investigate the cross-modal interaction effects of "má là" umami flavor (total of eight carriers) on the saltiness perception and effective sodium reduction in low-to-strong NaCl aqueous solutions (0.203 %-1.39 %) and oil-added systems (5 %, 10 %, 15 %, 20 %, 25 % canola oil, wt%), sixteen assessors were selected and two methods including saltiness intensity comparison with a category scale and rating with a generalized Labeled Magnitude Scale (gLMS) were used. The results showed PnSnUn carriers significantly enhance saltiness at moderate-to-strong NaCl solutions, and higher saltiness intensity with the addition of canola oil, especially at 25 % oil level. In addition, based on the developed Stevens' power function the sodium reduction was calculated, it was evident that two "má là" umami flavor combinations (one flavor combination was low "má", low "là" and moderate umami, and the other flavor combination with moderate "má", low "là" and moderate umami) were found to perform best with maximum sodium reduction of 18.88 % and 18 %, respectively, and when incorporating 25 % canola oil, the maximum sodium reduction raised by approximately 10 % (to 28.00 % and 28.42 %). This research not only confirmed the positive modulating effect of the "má là" umami flavor on saltiness perception in NaCl solutions, but also showed that the presence of oil further enhanced this effect. This work offered a new and promising insight into the development of foods with reduced sodium content while maintaining the saltiness properties.

SERS determination of hydroxy-α-sanshool in spicy hotpot seasoning: The strategy to restrain the interference of capsaicin and its mechanism

Hydroxy-α-sanshool (α-SOH) is the principal ingredient responsible for the numbing sensation in spicy hotpot. However, utilizing surface-enhanced Raman scattering (SERS) to analyze the α-SOH in hotpot seasoning is challenging due to the significant interference of capsaicin (CAP). Therefore, two schemes were proposed to address CAP interference in hotpot seasoning, namely laccase-catalyzed conversion and metal-organic framework (MOF) interaction. Among them, Fe-BTC MOF exhibited significant anti-interference effect and the underlying mechanism is elucidated. The motion of CAP aromatic ring was constrained by steric hindrance and electrostatic interactions of Fe-BTC. Additionally, the interaction between CAP aromatic ring and conjugated triene group in α-SOH was quenched, enhancing the α-SOH SERS signal. The proposed method had a significant anti-interference effect on α-SOH quantification in the presence of CAP, significantly enhancing the α-SOH SERS signal in a range of 0.85 to 4.00 × 10⁷. The linearity and reproducibility of the proposed hotpot seasoning testing method were also validated.

Changes in the physicochemical properties and antioxidant capacity of Sichuan hotpot oil

This study aimed to develop nutritious and healthy Sichuan hotpot oil. Four blended oil formulas were formulated using MATLAB based on the fatty acid composition of four base constituents (beef tallow, mutton tallow, peanut oil, and palm oil). The sensory characteristics, physicochemical properties, nutritional composition, harmful substances, and antioxidant capacity of the oils were analyzed during the boiling process. A blend of 60% beef tallow + 10% mutton tallow + 10% peanut oil + 20% palm oil exhibited a low level of peroxide (0.03 g/100 g) and malondialdehyde (0.04 mg/kg), and high phytosterol content (1028.33 mg/kg), which was the suitable hotpot blending oil. Furthermore, the changes in the physicochemical properties during boring were low, with a high retention rate of phytosterol (94.85%), and the levels of 3,4-benzopyrene (1.12 μg/kg) and 3-monochloropropane-1,2-diol ester (0.67 mg/kg) were both lower than the recommended limits. This study will provide a theoretical basis for the advancement of the hotpot oil industry.

Variation and Correlation Analysis of Flavour and Bacterial Diversity of Low-Salt Hotpot Sauce during Storage

Culinary circles have experienced a recent trend towards low-salt hotpot sauces. Here, changes in the physicochemical quality, flavour, and bacterial diversity of hotpot sauces with different salt concentrations were studied during storage. The results indicated that the peroxide and acid values of hotpot sauce increased gradually and that the quality began to deteriorate with storage. A storage temperature of 4 °C and salt concentration above 4.4% significantly reduced spoilage. The salt concentration had no significant effect on the flavour but extended storage resulted in significant differences in flavour reflected in the changes of sweet, sour, bitter, umami, aftertaste-A, abundance, organic sulphide, and alkanes. Significant differences were found in the bacterial composition between samples stored at different temperatures. Norank-f-o-Chloroplast was the main bacterium in the samples stored at low temperatures, which was beneficial for preservation. Bacillus was detected in 4.1% NaCl samples stored at 25 °C, directly promoting sauce spoilage and an unpleasant flavour. This bacterium signalled the spoilage of low-salt hotpot sauce stored at room temperature.

Research on non-destructive testing of hotpot oil quality by fluorescence hyperspectral technology combined with machine learning

Eating repeatedly used hotpot oil will cause serious harm to human health. In order to realize rapid non-destructive testing of hotpot oil quality, a modeling experiment method of fluorescence hyperspectral technology combined with machine learning algorithm was proposed. Five preprocessing algorithms were used to preprocess the original spectral data, which realized data denoising and reduces the influence of baseline drift and tilt. The feature bands extracted from the spectral data showed that the best feature bands for the two-classification model and the six-classification model were concentrated between 469 and 962 nm and 534-809 nm, respectively. Using the PCA algorithm to visualize the spectral data, the results showed the distribution of the six types of samples intuitively, and indicated that the data could be classified. Based on the modeling analysis of the feature bands, the results showed that the best two-classification models and the best six-classification models were MF-RF-RF and MF-XGBoost-LGB models, respectively, and the classification accuracy reached 100 %. Compared with the traditional model, the error was greatly reduced, and the calculation time was also saved. This study confirmed that fluorescence hyperspectral technology combined with machine learning algorithm could effectively realize the detection of reused hotpot oil.

Assessment of the Physicochemical Properties of Fragrant Rapeseed Blended Hotpot Oil by Principal Component Analysis

In this study, a nutritious, healthy Chongqing hotpot oil with excellent flavor was blended while considering nutrition, flavor, and health aspects. Four blended hotpot oils prepared from fragrant rapeseed, palm, sesame, and chicken oils were analyzed to determine their physicochemical properties, antioxidant capacities, levels of harmful substances, and nutritional compositions, and their sensory qualities were evaluated. Principal component analysis was performed to identify the best hotpot oil (10% chicken oil + 20% palm oil + 10% sesame oil + 60% fragrant rapeseed oil), which exhibited good antioxidant capacity (Oxidation Stability Index: 7.95 h; 2,2-diphenyl-1-picrylhydrazyl: 168.6 μmol/kg, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate): 116.7 μmol/kg, and ferric-reducing/antioxidant power: 63.9 μmol/kg), a high sensory score (7.7/10), stable physicochemical properties (acid value: 0.27 mg/g and peroxide value: 0.01 g/100 g), and high tocopherol (54.22%), and phytosterol retention (98.52%) after boiling for 8 h. Although the 3,4-benzopyrene content of this hotpot oil exceeded the EU standard after boiling for 7 h, the increase in the amount of harmful substances was the lowest.

Enhanced waste hot-pot oil (WHPO) anaerobic digestion for biomethane production: Mechanism and dynamics of fatty acids conversion

Resource depletion and climate changes due to human activities and excessive burning of fossil fuels are the driving forces to explore alternatives clean energy resources. Anaerobic digestion of bio-waste provides a unique opportunity to fulfil this objective through biogas production. The present study aimed to evaluate waste hot-pot oil (WHPO) at different feeding ratios as a novel lipidic waste for anaerobic mono-digestion. The highest recorded maximum biomethane potential (M_max) was 274.1 L kg^-1 VS at 1.2% WHPO, which showed significant differences with those of 0.8% and 1.6% (227.09 and 237.62 L kg^-1 VS, respectively). The changes in volatile fatty acids (VFAs), medium chain fatty acids (MCFAs), and long-chain fatty acids (LCFAs) as intermediates of WHPO decomposition were investigated before and after anaerobic digestion. Results showed efficient production and utilization of VFAs at all studied WHPO ratios, whereas the maximum utilization of VFAs (90-95%) was recorded in the reactors with up to 1.2 %WHPO. Although lipid conversion efficiency decreased by increasing the WHPO ratio, 81.2% lipid conversion efficiency was recorded at the highest applied WHPO treatment, which confirms the potential of WHPO as a promising feedstock for anaerobic digestion. The present results will have major implications towards efficient energy recovery and biochemical management of lipidic-waste through efficient anaerobic digestion.