农林科学最新文献

Cocoa is a high value product and therefore a potential target for economic adulteration with less expensive ingredients. Carob flour is less expensive than cocoa powder and is frequently cited as a potential cocoa substitute. While carob has legitimate uses as a cocoa replacement, these characteristics also make it a potential adulterant of cocoa powder. Direct analysis in real time mass spectrometry (DART-MS) is an ambient ionization MS technique that can be used to rapidly interrogate samples. Samples of cocoa powders, carob flours, and mixtures of the two were extracted with buffer and interrogated by DART-MS. The mass spectra were used to develop models to distinguish between cocoa powder and cocoa powder adulterated with carob. A principal component-linear discriminant analysis (PCA-LDA) model was used to discriminate between cocoa powder and cocoa powder amended with 15% carob flour. The accuracy using internal validation was 100%. Using an external validation dataset, the accuracy, precision, and recall were 96.0%, 94.8%, and 97.3%, respectively. These results demonstrate that DART-MS can be used to discriminate between cocoa powder and cocoa powder adulterated with 15% carob.

The use of microalgae as a source of food and pharmaceutical ingredients has garnered growing interest in recent years. Despite the rapid growth of the nutraceutical market, knowledge about the potential of bioactive molecules from microalgae remains insufficient. The present study aimed to investigate the biotechnological potential of the green microalga Desmodesmus armatus isolated from a semi-arid region of Brazil. The algal biomass was characterized in terms of gross biochemical composition, exopolysaccharide content, enzymatic inhibition capacity, and antioxidant, antibacterial, and hemolytic activities from solvents of different polarities (water, ethanol, acetone, and hexane). D armatus biomass had 40% of crude protein content, 25.94% of lipids, and 25.03% of carbohydrates. The prebiotic potential of exopolysaccharides from D armatus was demonstrated, which stimulated the growth of Lacticaseibacillus rhamnosus and Lactiplantibacillus plantarum bacteria strains. Moreover, the enzyme inhibition capacity for the proteases chymotrypsin (34.78%-45.8%) and pepsin (16.64%-27.27%), in addition to α-amylase (24.79%) and lipase (31.05%) was confirmed. The antioxidant potential varied between the different extracts, with 2,2-diphenyl-1-picrylhydrazyl sequestration values varying between 17.51% and 63.12%, and those of the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) method between 6.82% and 22.89%. In the antibacterial activity test, only the ethanolic extract showed inhibition against Listeria sp. (at minimum inhibitory concentration [MIC] = 256 µg mL^-1). This fraction also presented the highest significant levels of hemolysis (31.88%-52.45%). In summary, the data presented in the study suggest the presence of biocompounds with biotechnological and nutraceutical potential in the D armatus biomass. Future studies may evaluate the inclusion of this biomass in foods in order to increase their biological value.

Canine mucosal melanoma (CMM) is the most common oral malignancy in dogs and is significantly more aggressive than its cutaneous counterpart (CCM), yet the reasons for this disparity remain unclear. Cancer-associated stroma (CAS) plays a crucial role in tumour progression, but a detailed understanding of CAS in canine melanoma is missing. To assess stromal reprogramming, we analysed CAS from 21 CMM, 14 CCM and normal stroma from 10 skin and 9 oral mucosa samples by laser-capture microdissection followed by RNA sequencing. Results were assessed in relation to subtypes, prognostic factors including mitotic count (MC), ulceration, necrosis, pigmentation and immune cell infiltration (CD3, CD20 and CD68), scored using immunohistochemistry and RNA in situ hybridisation. Stromal reprogramming was evident in both subtypes but significantly more pronounced in CMM. Immune-excluded tumours exhibited higher MC than desert/cold ones. MC strongly correlated with genes associated with B-cells, T-helper cells and CTLA4 in CCM, suggesting CAS reprogramming to depend on tumour malignancy. Finally, we identify an immune-suppressive stromal signature in a subset of CMM characterised by the downregulation of key immune checkpoints and pathways. Together, these findings provide a solid foundation for understanding the role of CAS in canine melanoma, specific to cutaneous and mucosal subtypes.

Pre-metastatic niche (PMN) formation is essential for metastatic development and drives organotropism. Tumour-derived extracellular vesicles and soluble factors remodel the microenvironment of distant metastatic organs before subsequent metastasis. Dogs with osteosarcoma (OS) have proven to be excellent disease models for their human companions. Here, we show evidence of PMN formation in dogs with OS before metastasis. We necropsied and sampled lung tissues from dogs with naturally occurring treatment-naïve OS (n = 15) and control dogs without cancer (n = 10). We further divided dogs with OS into those having lung metastases (n = 5) and those without (n = 10). We stained formalin-fixed paraffin-embedded tissues using multiplex immunofluorescence to quantify the number of bone marrow-derived cells, monocytes and macrophages in the lung samples from each dog. The numbers of CD204⁺ macrophages, CD206⁺ macrophages and monocytes and CD11d⁺ bone marrow-derived cells (BMDCs) were significantly higher in the pre-metastatic lung of dogs with OS (n = 10) than in control dogs without cancer (n = 10). Furthermore, the total nucleated cell (DAPI⁺) density was higher before metastasis than in healthy lungs. In dogs with established metastases, the number of CD11d⁺ BMDCs was significantly lower than in the pre-metastatic lung, suggesting this recruitment is transient. Our study provides evidence of PMN existence in a naturally occurring cancer model similar to those observed in pre-clinical murine models. BMDCs are recruited to the lungs before metastases have developed. Dogs with OS may represent ideal candidates for assessing new PMN-targeting therapies.

CCNU (1-[2-chloroethyl]-3-cyclohexyl-1-nitrosurea), lomustine, is an oral alkylating agent in the nitrosourea subgroup. The dose-limiting toxicity of CCNU is neutropenia most frequently documented 7 days after its administration. Use of prophylactic antimicrobials to prevent chemotherapy-related febrile neutropenia (FN) and its associated morbidity and mortality has been well-documented in human oncology, but this information is limited in the veterinary literature. The purpose of this multi-institutional retrospective study was to assess whether antimicrobial prophylaxis reduced the risk of FN approximately 7 days after CCNU administration in tumour-bearing dogs. A secondary goal was to identify risk factors for fever development in neutropenic dogs. Two hundred dogs were included in the study. One hundred and fifty-three dogs (76.5%) were neutropenic at the first post-CCNU recheck. One hundred and six (69.3%) dogs received prophylactic antimicrobials and 47 (30.7%) did not. Of the 106 dogs on prophylactic antimicrobials, 8 (7.5%) developed FN. Of the 47 dogs in the no-prophylactic antimicrobials group, 4 (8.5%) developed FN. Use of prophylactic antimicrobials did not reduce the risk of development of FN (p = 0.84). Older age (> 9 y), lower weight and body surface area, and pre-treatment with chemotherapy or radiation therapy were significantly associated with development of FN (p = 0.009, p = 0.023, p = 0.015 and p = 0.01). Patients with a lower absolute neutrophil count, and a higher VCOG-CTCAE v2 neutropenia grade were also at an increased risk of developing FN (p = 0.01, p < 0.001). Additional studies may help establish guidelines for antimicrobial prophylaxis in dogs treated with CCNU, especially for those at high-risk for FN.

This study provides occurrence data for acrylamide in various foodstuffs, including those covered by Recommendation (EU) 2019/1888, from 210 samples purchased on the Belgian market. Detection frequencies exceeded 84% in potato-based products other than fries, vegetable crisps, black olives, cocoa powders, coffee substitutes and cereals and snacks. Large variations in acrylamide levels were found in cereals and snacks, with no correlation between cereal type or processing. Snacks containing chia did not show higher acrylamide levels than other cereal-based snacks. Maximum levels found were 4389 and 3063 µg kg^-1 in coffee substitutes and vegetable crisps, respectively. Potato-based products contained 2 to 27 times less acrylamide when prepared in oven, compared to deep fryer processing. Artificially oxidised "Californian-style" black olives contained five times more acrylamide than "Greek-style" olives. In bread, pastries, nuts, oilseeds, dried fruits and confectionaries, detection frequencies varied from 27 to 69% and the average acrylamide content was <30 µg kg^-1.

Dental Fluorosis (DF) is one of the negative outcomes of excessive fluoride (F) intake through food sources. This systematic review aimed to compare F content in two important food sources for infants, Mother's Milk (MoM) and Infant Formula (IF), and then evaluate the risk of DF related to F in those two types of food. For this purpose, 181 studies were initially found by searching the relevant keywords in widely recognized databases, including Google Scholar, Scopus, Science Direct, and PubMed. Then, 29 final studies were selected considering the inclusion and exclusion criteria. The results showed that the F level of MoM in five out of nine (55.5%) studies and its overall average worldwide does not comply with the European Food Safety Authority (EFSA) guideline (100 µg/L). Therefore, MoM's value of F must be continuously monitored, and risk mitigation solutions must be used to reduce F. Accordingly, tracking F in drinking water, tea, and food consumed by lactating mothers (LMs) was the essential measure that could lead to the reduction of F of MoM. The level of F of IF was much lower than its value in MoM. The estimated hazard quotient (HQ) of DF for both types of food was lower than the acceptable level (HQ = 1), but, due to other sources of F intake, it is necessary to use control solutions to reduce the level of F in MoM and IF consumed by infants.

Infant cereals are typically the first foods introduced as complementary foods. Cereals used to elaborate complementary foods, such as wheat, maize and rice, are susceptible to mycotoxin contamination. Among mycotoxins, fumonisins have been epidemiologically associated, in humans, with oesophageal cancer, neural tube defects and stunting. Fumonisins have been found in maize and wheat grains in Argentina. In the present study, a survey was conducted to determine their occurrence in 82 wheat-based and multicereal-based infant cereal items collected from retail stores in Rio Cuarto, Argentina, using HPLC-MS. Of these samples, 84% showed FBs contamination with levels ranging from 0.05 to 992 μg/kg). Although FB₁ was the most prevalent fumonisin, FB₂ was found at higher levels. Most samples had levels below the limit of 200 μg/kg set for Argentinean cereal products for children. The outcome of this survey provides information on the naturally presence of fumonisin in infant cereal intended for children in Argentina, which can be helpful to consider relevant monitoring programmes.

Arsenic (As) occurs naturally in different forms and oxidation states. Amongst them, inorganic arsenic (iAs) is classified as both genotoxic and carcinogenic whilst other organic arsenic species are considered less toxic. As in rice is mainly present in the form of iAs which therefore poses a health risk to populations that consume rice as a staple food. In 2011, the Joint Food and Agriculture Organisation/World Health Organisation Expert Committee on Food Additives determined the iAs benchmark dose lower confidence limit for a 0.5% increased incidence of lung cancer in humans (BMDL_0.5) which computed to be 3.0 μg/kg body weight (bw)/day. However, the European Food Safety Authority (EFSA) has recently lowered the BMDL_0.5 of iAs to 0.06 μg iAs/kg bw per day based on a low risk of bias case-control/cohort study on skin cancer as a Reference Point (RP). Subsequently, EFSA established a BMDL₁₀ of 18.2 mg monomethylarsenic (V) (MMA(V))/kg bw/day and 1.1 mg dimethylarsenic (V) (DMA(V))/kg bw/day as RPs with reference to studies on skin cancer and urinary bladder tumours in rats respectively. Therefore, As speciation is essential when conducting dietary exposure assessment. Recent studies showed thiolated counterparts of MMA and DMA were found in certain foodstuffs, especially grain. However, these thiolated As species were not recognised in acidic, basic or peroxide systems as they transformed to MMA and DMA in these extractants. Therefore, one of the objectives of this review was to assess whether published analytical methods are fit for As speciation analysis, especially for iAs, MMA and DMA, in foodstuffs. Besides, discussion was conducted on whether limits of detection are sufficiently low for dietary exposure assessment with respect to recently established RPs of iAs, MMA and DMA when an upper bound approach is applied. Moreover, possible future research gaps are identified based on current knowledge and existing literature.