Quality by design approach to optimize cladodes soluble fiber processing extraction in Opuntia ficus indica (L.) Miller

Arthrobacter sp. Inoculation Improves Cactus Pear Growth, Quality of Fruits, and Nutraceutical Properties of Cladodes

A study was undertaken to determine the effects of a strain of Arthrobacter sp., a Plant Growth-Promoting Bacteria (PGPB), on plant phenology and qualitative composition of Opuntia ficus-indica (L.) Mill. fruits and cladodes. The strain was inoculated in soil, and its effects on cactus pear plants were detected and compared to nontreated plants. Compared to the latter, the treatment with bacteria promoted an earlier plant sprouting (2 months before the control) and fruitification, ameliorating fruit quality (i.e., improved fresh and dry weight: + 24% and + 26%, respectively, increased total solid content by 30% and polyphenols concentrations by 22%). The quality and quantity of monosaccharides of cladodes were also increased by Arthrobacter sp. with a positive effect on their nutraceutical value. In summer, the mean values of xylose, arabinose, and mannose were significantly higher in treated compared to not treated plants (+ 3.54; + 7.04; + 4.76 mg/kg d.w. respectively). A similar trend was observed in autumn, when the cladodes of inoculated plants had higher contents, i.e., 33% xylose, 65% arabinose, and 40% mannose, respect to the controls. In conclusion, Arthrobacter sp. plays a role in the improvement of nutritional and nutraceutical properties of cactus pear plants due to its capabilities to promote plant growth. Therefore, these results open new perspectives in PGPB application in the agro-farming system as alternative strategy to improve cactus pear growth, yield, and cladodes quality, being the latter the main by-product to be utilized for additional industrial uses.

A Comparative Study on Extraction and Physicochemical Properties of Soluble Dietary Fiber from Glutinous Rice Bran Using Different Methods

The methods of hot water extraction and ultrasound-assisted enzymatic treatment were applied for extracting the soluble dietary fiber from the glutinous rice bran in the study. Based on the single factor experiment for the hot water method, the optimum parameters of the extraction time of 120 min, solid-liquid ratio 1:20 (w/v), and pH 8.0, as well as the extraction temperature 80 °C, were obtained, while the yield and purity of SDF reached 31.83 ± 0.06% and 93.28 ± 0.27%, respectively. Furthermore, the SDF yield was improved to 34.87 ± 0.55% by using the ultrasound-assisted enzymatic treatment under the optimum conditions of cellulase dosage 9 × 103 U/g and ultrasonic temperature of 50 °C. Similar polysaccharide compositions were detected based on the infrared spectroscopic analysis. Compared with the SDF obtained from hot water extraction, the whiteness, solubility, water holding capacity, and swelling properties of SDF extracted by ultrasound-assisted enzymatic method improved significantly. These results demonstrated that both two strategies could be applied to SDF extraction in practical production, and the ultrasound-assisted enzymatic method might be an effective tool to improve the functional properties of SDF.

Prickly Pear Cacti (Opuntia spp.) Cladodes as a Functional Ingredient for Hyperglycemia Management: A Brief Narrative Review

The worldwide prevalence of obesity is increasing along with its comorbidities, including type 2 diabetes mellitus (T2DM). From a pathophysiological perspective, T2DM arises as a consequence of insulin resistance and pancreatic β-cell dysfunction, which together induce chronic hyperglycemia. The pharmacological treatment of T2DM specifically focuses on its management, rather than remission, with a lack of pharmacological agents to prevent the onset of the disease. Considering the role of unhealthy dietary patterns on the development of T2DM, identifying novel food ingredients and bioactive substances may provide new avenues by which to address the T2DM epidemic. In this brief review, we have summarized the latest findings on the consumption of the prickly pear (PP; Opuntia spp.) cladode as a potential nutritional tool for the management of hyperglycemia. The consumption of prickly pear cladodes was reported to exert hypoglycemic effects, making it a potential cost-effective nutritional intervention for the management of T2DM. Several studies have demonstrated that the consumption of prickly pear cladodes and the related products reduced post-prandial glucose levels. The cladodes’ high fiber content may be implicated in improving glycemic control, by affecting glucose absorption and effectively slowing its release into the blood circulation. Given these potential hypoglycemic effects, prickly pear cladodes may represent a potential functional food ingredient to improve glycemic control and counter the negative metabolic effects of the modern Western diet. Nonetheless, in consideration of the lack of evidence on the chronic effects of the prickly pear cladode, future research aimed at evaluating its long-term effects on glycemic control is warranted.

Mucilages: sources, extraction methods, and characteristics for their use as encapsulation agents

The increasing interest in the use of natural ingredients has driven keen research and commercial interest in the use of mucilages for a range of applications. Typically, mucilages are polysaccharide hydrocolloids with distinct physicochemical and structural diversity, possessing characteristic functional and health benefits. Apart from their role as binding, thickening, stabilizing, and humidifying agents, they are valued for their antimicrobial, antihypertensive, antioxidant, antiasthmatic, hypoglycemic, and hypolipidemic activities. The focus of this review is to present the range of mucilages that have been explored as encapsulating agents. Encapsulation of food ingredients, nutraceutical, and pharmaceutical ingredients is an attractive technique to enhance the stability of targeted compounds, apart from providing benefits on delivery characteristics. The most widely adopted conventional and emerging extraction and purification methods are explained and supplemented with information on the key criteria involved in characterizing the physicochemical and functional properties of mucilages. The unique traits and benefits of using mucilages as encapsulation agents are detailed with the different methods used by researchers to encapsulate different food and bioactive compounds.

Mucilages from Different Plant Species Affect the Characteristics of Bio-Mortars for Restoration

The need for compatible materials for the preservation of cultural heritage has resulted in the revival of lime-based mortar technology and other applications. This work investigates the cohesion and integrity of lime mortars added with fresh mucilage extracted from five plants and evaluates their bioreceptivity for long-term durability. Specimens of lime mortars added with 2.5% of fresh mucilage extracted from Aloe vera, Cylindropuntia californica, Opuntia engelmannii, Opuntia ficus-indica and Salvia hispanica mucilages were analyzed for color change (colorimetry), cohesion (ultrasound measurements), integrity (X-rays) and bioreceptivity (microbiological tests).The internal structure of the specimens added with Cacti mucilages shows better compactness, and no color change was noticed in the bio-mortars also after aging. The bioreceptivity response of mortars inoculated with bacteria, fungi and a photosynthetic biofilm was quite different. Specimens added with Aloe and Cylindropuntia mucilages showed a higher extent of bioreceptivity than the control; the specimens of bio-mortars added with Opuntia engelmannii, Opuntia ficus-indica and Salvia hispanica mucilages did not appear, up to threemonths after the contamination, any microbial growth. These results indicate that the addition of mucilage improves the mortar qualities, but the choice of the plant mucilage must be carefully evaluated since it can be responsible for changes in the bioreceptivity of the mortar.

Self-Powered Flexible Sour Sensor for Detecting Ascorbic Acid Concentration Based on Triboelectrification/Enzymatic-Reaction Coupling Effect

Artificial sensory substitution systems can mimic human sensory organs through replacing the sensing process of a defective sensory receptor and transmitting the sensing signal into the nervous system. Here, we report a self-powered flexible gustation sour sensor for detecting ascorbic acid concentration. The material system comprises of Na2C2O4-Ppy with AAO modification, PDMS and Cu wire mesh. The working mechanism is contributed to the triboelectrification/enzymatic-reaction coupling effect, and the device can collect weak energy from body movements and directly output triboelectric current without any external power-units. The triboelectric output is affected by AA concentration, and the response is up to 34.82% against 15.625 mM/L of AA solution. Furthermore, a practical application in detecting ascorbic acid concentration of different drinks has been demonstrated. This work can encourage the development of wearable flexible electronics and this self-powered sour sensor has the potential that can be acted as a kind of gustatory receptors to build electronic tongues.