Authenticity of freeze-dried açai pulp by near-infrared spectroscopy

Food authentication, current issues, analytical techniques, and future challenges: A comprehensive review

Food authentication and contamination are significant concerns, especially for consumers with unique nutritional, cultural, lifestyle, and religious needs. Food authenticity involves identifying food contamination for many purposes, such as adherence to religious beliefs, safeguarding health, and consuming sanitary and organic food products. This review article examines the issues related to food authentication and food fraud in recent periods. Furthermore, the development and innovations in analytical techniques employed to authenticate various food products are comprehensively focused. Food products derived from animals are susceptible to deceptive practices, which can undermine customer confidence and pose potential health hazards due to the transmission of diseases from animals to humans. Therefore, it is necessary to employ suitable and robust analytical techniques for complex and high-risk animal-derived goods, in which molecular biomarker-based (genomics, proteomics, and metabolomics) techniques are covered. Various analytical methods have been employed to ascertain the geographical provenance of food items that exhibit rapid response times, low cost, nondestructiveness, and condensability.

Near infrared spectroscopy and smartphone-based imaging as fast alternatives for the evaluation of the bioactive potential of freeze-dried açai

The development of green analytical techniques for food industry quality control has become an important issue in the context of the fourth industrial revolution. In this sense, near infrared spectroscopy (NIR) and smartphone-based imaging (SBI) were applied to evaluate the bioactive potential of freeze-dried açai pulps. For this purpose, reference results of ninety-six samples were obtained by determining total anthocyanins (TAC), polyphenol content (TPC), and antioxidant capacity (DPPH, ORAC and TEAC) by traditional methods and correlated to NIR spectra and SBI to build predictive models based on partial square least (PLS) regression. In summary, the NIR-PLS models showed better performance for predicting the TAC, TPC and antioxidant capacity of studied samples; considering the parameters of merit, such as coefficient of determination (0.8) and residual prediction deviation (RPD) (2.2) compared to the SBI-PLS models (0.7 and lower 1.5, respectively). The better performance of NIR-PLS could be potentially justified by a higher sensitivity of the NIR equipment than the smartphone images. In conclusion, these results show that the proposed alternative methods are promising tools for the future context of the 4.0 food industry.

Chemical Composition and Bioactive Properties of Commercial and Non-Commercial Purple and White Açaí Berries

Chemical composition analysis of açaí extracts revealed higher levels of total polyphenol content in purple açaí samples for both commercial (4.3–44.7 gallic acid equivalents mg/g) and non-commercial samples (30.2–42.0 mg/g) compared to white (8.2–11.9 mg/g) and oil samples (0.8–4.6 mg/g). The major anthocyanin compounds found in purple açaí samples were cyanidin-3-glucoside and cyanidin-3-rutinoside with total concentrations in the range of 3.6–14.3 cyanidin-3-glucoside equivalents mg/g. The oligomeric proanthocyanidins were quantified in the range of 1.5–6.1 procyanidin B1 equivalents mg/g. Moreover, açaí presented significant levels of calcium, magnesium, manganese, iron, zinc and copper, essential minor and trace elements, in comparison with other berries. All of the açaí extracts at 50 μg/mL potently inhibited the release of reactive oxygen species in lipopolysaccharide-stimulated RAW 264.7 murine macrophage cells, but none inhibited the release of nitric oxide. Furthermore, all the açaí samples demonstrated potential as wound healing agents due to the high levels of migration activity in human fibroblast cells.

Extraction of Anthocyanins and Total Phenolic Compounds from Açai (Euterpe oleracea Mart.) Using an Experimental Design Methodology. Part 1: Pressurized Liquid Extraction

Currently, açai is one of the most important fruits present in the world. Several studies have demonstrated its high content in phenolic compounds and anthocyanins. Both of them are responsible of interesting properties of the fruit such as anti-inflammatory, antioxidant or anticancer. In the present study, two optimized pressurized liquid extraction (PLE) methods have been developed for the extraction of anthocyanins and total phenolic compounds from açai. A full factorial design (Box–Behnken design) with six variables (solvent composition (25–75% methanol-in-water), temperature (50–100 °C), pressure (100–200 atm), purge time (30–90 s), pH (2–7) and flushing (50–150%)) were employed. The percentage of methanol in the extraction solvent was proven to be the most significant variable for the extraction of anthocyanins. In the case of total phenolic compounds, the extraction temperature was the most influential variable. The developed methods showed high precision, with relative standard deviations (RSD) of less than 5%. The applicability of the methods was successfully evaluated in real samples. In conclusion, two rapid and reliable PLE extraction methods to be used for laboratories and industries to determine anthocyanins and total phenolic compounds in açai and its derived products were developed in this work.