Protein concentrates from edible insect tenebrio molitor: development of extraction methods and techno-functional characterization

The goals of this work were to develop extraction techniques that allowed us to obtain protein concentrates from the edible insect Tenebrio molitor larvae, with high protein purity as well as good techno-functional characteristics. Two different protein extraction methods were developed, based on isoelectric point precipitation or membrane ultrafiltration. For both methods, dried T. molitor larvae was defatted with the Soxhlet method with ethanol as a solvent. The defatted fraction was then homogenized in a NaOH solution with the homogenate being recovered and centrifuged.. The supernatant (S) and the pellet fractions were recovered. For the isoelectric point precipitation method, the recovered supernatant pH was modified to 4.546 and the precipitate was centrifuged at 5000 rpm for 30 minutes at 4ºC. The pellet fraction was freeze-dried (IP). For the membrane ultrafiltration, the supernatant was filtrated with a 50 kDa membrane with the retained (> 50 kDa) and filtered ( 50 kDa fraction had protein contents above 80% while the 50 kDa only attained a protein recovery rate of 31% and 32% respectively. Concerning the protein profiles, the >50 kDa fraction had a very similar profile to the supernatant, while the IP fraction was composed by protein with higher molecular weight. The >50 kDa fraction had higher L* (lightness) and b* (yellowness) color than the IP fraction or the defatted or oven-dried samples. Additionally, the samples presented better techno-functional properties than the dried or defatted sample and the >50 kDa fraction had better properties than commercial protein concentrates (whey protein or pea protein). Protein extraction method based on ultrafiltration led to a protein concentrate with high purity and acceptable techno-functional properties, and can function as an alternative to the more common method based on isoelectric point precipitation.info:eu-repo/semantics/publishedVersio

Valorization of lignin from sugarcane by-products: review

The valorization of sugarcane industry by-products is fundamental to increase competitiveness on a circular economy point of view. Straw and bagasse are by-products with huge potential as source of added value ingredients. Lignin is an abundant component found in these by-products with proved biological activity, particularly antimicrobial, antioxidant and UV protection. Additionally, recent applications on materials have been reported for lignin-based products.info:eu-repo/semantics/publishedVersio

Development and characterization of a novel sustainable probiotic goat whey cheese containing second cheese whey powder and stabilized with thyme essential oil and sodium citrate

Probiotic goat whey cheeses with added second cheese whey powder (SCWP) were developed, resulting in creamy and spreadable products. The products contained Lactobacillus rhamnosus and Bifidobacterium animalis, as well as thyme essential oil and sodium citrate. Matrices of probiotic whey cheeses, with and without additives, were produced and stored at 5 °C for 21 days. Microbial and chemical profiles were evaluated weekly. The composition of the optimum matrix, formulated with whey cheese, probiotic culture, SCWP, thyme essential oil and sodium citrate (WCPSTC) was, expressed in % (w/w): protein (10.78 ± 0.08), fat (7.59 ± 0.03), dry matter (25.64 ± 0.13), ash (2.81 ± 0.02) and lactose (3.16 ± 0.04). Viable cell numbers of both probiotic cultures in matrix WCPSTC remained above 107 CFU g−1. This finding is of the utmost importance since it proves that both probiotic bacteria, citrate and thyme essential oil can be combined in order to increase the shelf-life and functional value of dairy products. All matrices’ pH values decreased during storage, yet only matrix WCPSTC remained above 5.0 pH units. The results indicated that the development of a probiotic whey cheese incorporating a dairy by-product, SCWP, is possible without compromising its chemical, microbiological or sensorial stability.info:eu-repo/semantics/publishedVersio

Phytochemical composition, antioxidant and antifungal activity of thymus capitatus, a medicinal plant collected from Northern Morocco

Thymus capitatus is a Mediterranean endemic plant commonly known as “Zaïtra” in northern Morocco. As T. capitatus is widely used in traditional medicine and food, this present work aims to investigate the chemical compositions and biological activities of the T. capitatus leaves essential oil (TcLEO), acetonic (TcLAE), and methanolic extract (TcLME). The spectrophotometric determination demonstrated that T. capitatus is a natural source rich in phenolic contents (TPC) and flavonoid contents (TFC) and that TcLME revealed the highest TPC and TFC than TcLAE and TcLEO. The LC-MS analysis of phenolic compounds showed that paraben acid was predominant in both TcLME and TcLAE, followed by cinnamic acid and p-hydroxybenzoic acid. GC-MS analysis of the TcLEO revealed the presence of a total of 10 compounds, which were predominated by carvacrol. The antioxidant activity by ORAC was observed to be significantly higher in TcLEO and TcLAE than in TcLME. All samples used to assess DNA degradation effectively prevented DNA oxidation and, at the same time, had a prooxidant effect. The genotoxicity test showed that the T. capitatus were devoid of any mutagenic activity. Concerning antifungal activity, all samples were able to inhibit the growth of all microorganisms tested at low concentrations. TcLAE showed higher activity than TcLME, and in general, dermatophytes were more susceptible, being Microsporum canis the most sensitive one. Overall, the results obtained from this study confirm the wide uses of T. capitatus. Furthermore, the finding results suggest that the T. capitatus essential oil and extracts can be highly useful for pharmaceutical industries.info:eu-repo/semantics/publishedVersio

Addition of probiotic bacteria in a semi-hard goat cheese (coalho): survival to simulated gastrointestinal conditions and inhibitory effect against pathogenic bacteria

In this study, the survival of the probiotics Lactobacillus acidophilus (LA-5), Lactobacillus casei subsp. paracasei (L. casei 01) and Bifidobacterium lactis (BB12) incorporated in a Brazilian semi-hard goat cheese (coalho) when exposed to in vitro simulated conditions of digestion was assessed. The inhibitory effects of these probiotic bacteriawere also evaluated against Listeriamonocytogenes and Staphylococcus aureus in the goat coalho cheese during refrigerated storage. At the end of the in vitro digestion, all of the probiotic tested strains presented decreased (p b 0.05) viable cell counts (5.5–6.0 log cfu/g) with respect to those determined before exposure to the mouth conditions (7–8 log cfu/g). L. casei subsp. paracasei presented inhibition rate of 7.87% and 23.63% against S. aureus on the 14th and 21st day of storage at 10 °C, respectively; against L. monocytogenes these values were 12.96 and 32.99%. Positive inhibition rates of B. lactis toward S. aureus were found on the 1st, 14th and 21st days of storage (16.32%, 10.12% and 3.67%, respectively); and against L. monocytogenes only on the 1st day of storage (3.28%). From these results, goat coalho cheese could be an interesting carrier of probiotic strains of L. acidophilus, L. casei subsp. paracasei and B. lactis. Moreover, L. casei subsp. paracasei, could be used as protective culture for delaying the growth of S. aureus and L. monocytogenes in goat coalho cheese.info:eu-repo/semantics/publishedVersio