Evolution of Food Safety Features and Volatile Profile in White Sturgeon Caviar Treated with Different Formulations of Salt and Preservatives during a Long-Term Storage Time

Natural flavonols as probes for direct determination of borax: From conventional fluorescence analysis to paper-based smartphone sensing

Borax is strictly regulated in the food processing and pharmaceutical industry due to its physiological toxicity, and the development of a direct analytical method is essential for effectively monitoring the borax abuse. In this work, the fluorescence properties of flavonoids, including flavones, isoflavones and flavonols, were systematically investigated from aqueous to borax solutions, and it was found that the weak intrinsic fluorescence of flavonols could be pervasively sensitized by borax. A natural flavonol, morin, was subsequently chosen as a representative probe to develop a turn-on fluorescence sensing method for borax analysis, which achieved a linear response spanning four orders of magnitude with a detection limit of 1.07 μM (0.22 μg mL-1 in terms of Na2B4O7 content). Furthermore, a smartphone-assisted paper-based test device was designed and constructed by 3D printing technology. Using morin-impregnated test strips as the carrier, the borax could be visually detected by the RGB signals of the captured images, with a detection limit of 0.13 mM (27.05 μg mL-1 for Na2B4O7). Combining ion exchange treatment for food samples and sodium periodate oxidation for drug samples, the developed methods were successfully applied for the direct analysis of borax in various products with the recoveries of 86.9-106.3% for traditional fluorescence analysis and 82.7-108.8% for smartphone-assisted fluorescence sensing. The fluorescence property of the morin-borax system was studied using time-dependent density functional theory, and the sensing mechanism was discussed in conjunction with experimental research.

Unveiling the aromatic differences of low-salt Chinese horse bean-chili-paste using metabolomics and sensomics approaches

To achieve salt reduction while ensuring flavor quality of Chinese horse bean-chili-paste (CHCP), we comprehensively explored the effect of indigenous strains Tetragenococcus halophilus and Candida versatilis on the aroma profiles of low-salt CHCP by metabolomics and sensomics analysis. A total of 129 volatiles and 34 aroma compounds were identified by GC × GC-MS and GC-O-MS, among which 29 and 20 volatiles were identified as significant difference compounds and aroma-active compounds, respectively. Inoculation with the two indigenous strains could effectively relieve the undesired acidic and irritative flavor brought by acetic acid and some aldehydes in salt-reduction samples. Meanwhile, inoculated fermentation provided more complex and richer volatiles in low-salt batches, especially for the accumulation of 3-methylbutanol, 1-octen-3-ol, benzeneacetaldehyde, phenylethyl alcohol, and 4-ethyl-phenol etc., which were confirmed as essential aroma compounds of CHCP by recombination and omission tests. The research elucidated the feasibility of bioturbation strategy to achieve salt-reducing fermentation of fermented foods.

Effect of coating with chitosan enriched with different borates on the shelf life of fish fillet

BACKGROUND

In this study, the effects of biofilm coatings obtained by immobilization of different borates - namely borax (BX), colemanite (COL), and ulexite (UX) - with chitosan (Ch) on the shelf life of rainbow trout fillets were investigated. The immobilization and characterization of borates in Ch were confirmed by scanning electron microscopy, Fourier transform infrared spectroscopy, and zeta potential analysis. In determining the shelf life of fillets that were covered by immersion and stored for 15 days, microbiological (total aerobic mesophilic, psychrotrophic, lactic acid, Pseudomonas, and Enterobacteriaceae bacteria counts) and chemical analyses (total volatile basic nitrogen, thiobarbituric acid reactive substance, and pH levels) were performed at 3 day periodic intervals. In addition, the biodegradation of borates was determined using inductively coupled plasma mass spectrometry in biofilm-coated fillets on the 1st, 8th, and 15th storage days.

RESULTS

The microbial results of the coatings enriched with borates (BX, COL, and UX) at different levels (0, 0.03, and 0.06 mg L^-1 ) (due to the immobilization with Ch) show the shelf life was extended by 3-6 days in all of the treatment groups compared with the control.

CONCLUSION

It was concluded that BX, COL, and UX coatings enriched by immobilization with Ch increase shelf life and improve fillet quality. In addition, the enrichment of BX, COL, and UX with Ch showed explicit natural protective effects. This study demonstrates that Ch-enriched coatings of BX, COL, and UX can be used as natural bioactive nanocarriers to provide bioactive food ingredients in the seafood processing industry. © 2023 Society of Chemical Industry.

Microbiological Quality and Organoleptic Property of Meat and Fish Preserved with Oil from Dacryodes Edulis Seed

The bioactive compounds contributing to aroma and natural antimicrobial potential of oil from Dacryodes edulis seed can be harnessed in food industries as food preservatives. This study therefore, reveals the preservative effect and organoleptic property of meat and fish preserved with oil from D. edulis seed. Proximate and mineral analysis of oil were carried out using standard methods. Preservative quality of oil on fish and meat was investigated at 4°C and 37°C. Organoleptic property of preserved fish and meat was determined using trained panellists. Fat, protein, carbohydrates, crude fibre, ash and moisture content of oil from D. edulis seed are 55.7%, 18.7%, 10.8%, 7.1%, 4.6% and 3.1%, respectively. Potassium (106.5 µg/g) and phosphorous (102.5 µg/g) have the relatively highest values compared (p<0.05) to other minerals like zinc, iron, calcium, magnesium, and sodium. Better preservative property of oil was observed on fried fish and meat kept at 4°C with no microbial growth. The highest microbial load (3.95 × 106 cfu/g) occurred in fresh chicken coated with oil from D. edulis seed after 7 days of preservation. Fish and meat fried with oil from D. edulis seed were well accepted (9.00) than those fried with groundnut oil (3.50). Oil from D. edulis seed is an edible oil that can be utilized as alternative vegetable oil with natural preservatives and embedded nutrients.