Total Free Amino Acids Research Articles

Compost Improving Morphophysiological and Biochemical Traits, Seed Yield, and Oil Quality of Nigella sativa under Drought Stress

This study aimed to determine the effects of compost amendment on the soil properties, as well as the morphophysiological responses, seed yield, oil content, and fatty-acid profile. of Nigella sativa plants under drought stress conditions. In a split-plot design, the field experiment was carried out during two seasons (2020/2021 and 2021/2022), involving three irrigation regimes (named I100, I75, and I50 of crop evapotranspiration) with three levels of compost application (C0, C15, and C30). Soil porosity, permeability, pore geometry, water-holding capacity, organic content, and soil cation exchangeable capacity were improved in response to applied compost levels. The growth, physiology, biochemistry, and yield characteristics of Nigella sativa plants were positively affected by compost addition but negatively affected by increasing water stress severity. Deficit irrigation regimes increased osmoprotectant substances (i.e., proline, total free amino acids, carbohydrates, and total soluble sugar). Compared to the control (I100), deficit irrigation (I50) reduced fixed and essential oil by 16.64% and 39.57% over two seasons. Water stress increased the content of saturated fatty acids, while unsaturated fatty acids decreased. Compost application of (C30) resulted in a significant increase in seed yield, fixed oil, and essential oil of Nigella sativa plants by 34.72%, 46.55%, and 58.11% respectively, compared to the control (C0). Therefore, this study concluded that compost amendment improved soil properties and significantly mitigated the detrimental effects of drought on Nigella sativa plants, resulting in a considerable increase in seed yield and its oil content, particularly polyunsaturated fatty acids, which are distinguished by their beneficial effects on human health.

효소 및 미생물 복합체를 사용한 인비트로 루왁 커피의 품질 특성

In vitro luwak coffee was produced using enzyme-microbial complexes. The coffee quality of non-fermented coffee beans (NFC) and fermented coffee beans (FC) was compared. The total free amino acid content was higher in FC than in NFC. The levels of glutamic acid and γ-amino-n-butyric acid in NFC were higher than those in FC; however, the contents of essential amino acids, such as lysine, leucine, and valine, in FC were higher than in NFC. During fermentation, the sucrose content decreased, whereas the fructose and glucose contents increased (p<0.001). The chromaticity of the coffee extract showed higher lightness (L), redness (a), and yellowness (b) values in FC than those in NFC. The caffeine content was significantly lower in FC (696.94±0.04 μg/mL) compared to that in NFC (1,130.22±1.55 μg/mL) (p<0.001). Conversely, the polyphenol and chlorogenic acid contents were significantly higher ​​in NFC than in FC (p<0.001). Electronic nose analysis indicated considerable differences between the volatile aromatic components in NFC and FC. Sensory scores were significantly higher for FC than those for NFC. Therefore, the fermentation of coffee beans using enzyme-microbial complexes altered the chemical components, which promoted the Maillard reaction during the coffee bean roasting process. These results suggest the possibility of producing in vitro luwak coffee with better flavor and lower caffeine content.

효소 및 미생물 복합체를 사용한 인비트로 루왁 커피의 품질 특성

In vitro luwak coffee was produced using enzyme-microbial complexes. The coffee quality of non-fermented coffee beans (NFC) and fermented coffee beans (FC) was compared. The total free amino acid content was higher in FC than in NFC. The levels of glutamic acid and γ-amino-n-butyric acid in NFC were higher than those in FC; however, the contents of essential amino acids, such as lysine, leucine, and valine, in FC were higher than in NFC. During fermentation, the sucrose content decreased, whereas the fructose and glucose contents increased (p<0.001). The chromaticity of the coffee extract showed higher lightness (L), redness (a), and yellowness (b) values in FC than those in NFC. The caffeine content was significantly lower in FC (696.94±0.04 μg/mL) compared to that in NFC (1,130.22±1.55 μg/mL) (p<0.001). Conversely, the polyphenol and chlorogenic acid contents were significantly higher ​​in NFC than in FC (p<0.001). Electronic nose analysis indicated considerable differences between the volatile aromatic components in NFC and FC. Sensory scores were significantly higher for FC than those for NFC. Therefore, the fermentation of coffee beans using enzyme-microbial complexes altered the chemical components, which promoted the Maillard reaction during the coffee bean roasting process. These results suggest the possibility of producing in vitro luwak coffee with better flavor and lower caffeine content.

Assessment of the Quality Characteristics of Stropharia rugosoannulata Subjected to Five Different Drying Methods

The effect of solar drying (SD), room-temperature shaded drying (RSD), hot-air drying (HD), vacuum freeze drying (VFD), and microwave drying (MD) was compared on the sensory quality, nutrient substances, bioactive constituents, and antioxidant activities of dried Stropharia rugosoannulata. The results revealed that, in comparison with SD, RSD, HD, and MD, VFD mushrooms exhibited a better appearance with less shrinkage and an ideal colour with lower a colour difference. Meanwhile, a significantly higher content ( p < 0.05 ) of protein, carbohydrate, total sugar, and vitamin C was retained in VFD samples. The HD and VFD samples both had abundant total free amino acids and best met the ideal protein standard. Furthermore, VFD had advantages in terms of better preserving bioactive constituents and stronger antioxidant activities compared to other treatments. Therefore, the VFD-dried S. rugosoannulata obtained a better overall quality compared to the other four drying methods.

Relationship between physicochemical properties and microbial structural distribution of Chinese-style and Salami fermented sausages

This study insightfully analyzed the relationship between chemical composition change, volatile flavor compounds (VFCs) and microbial structural distribution of Chinese-style (CFS) and Salami fermented sausages (WFS) during their fermentation processes (FP). The results showed pH, acid and peroxide values of CFS were higher than WFS during whole FP (38 d). At the end of fermentation (38 days), the pH value of CFS and WFS were 5.70 ± 0.01 and 5.43 ± 0.01, respectively. The acid value was 9.89 ± 0.38 and 6.29 ± 0.28 mg/g, respectively. The peroxide value was 0.21 ± 0.01 and 0.14 ± 0.01 g/100g, respectively. During 0–13 d, moisture contents of CFS were higher than WFS, while opposite in 14–38 d. Nitrite contents of WFS were higher than CFS. The total free-amino acid contents of CFS were significantly lower than WFS (p < 0.05). The six groups of main VFCs in the two sausages were aldehydes, acids, alcohols, esters, ketones and hydrocarbons, respectively, and the contents of ketone in CFS were higher than WFS. However, the bacterial abundance in CFS increased gradually, while that in WFS's increased firstly and then decreased. The abundances and diversities of fungi in WFS were higher than CFS. In brief, microbial structural distribution formed an obvious impact on the chemical composition quality of fermented sausages, the above results provided data support for the production improvement of Chinese-style and Salami fermented sausages.

Nutritional composition of the wild variety of edible vegetables consumed by the tribal community of Raipur, Chhattisgarh, India

Humans established relations with food with their existence on earth. In various parts of the world, different types of vegetation are used as food material. Chhattisgarh, where numbers of tribes exist and used a leafy portion of various plants as a food material. The present study evaluated the total protein, total carbohydrate, and total free amino acid content in leafy vegetables used in Chhattisgarh. Total protein was estimated by Lowry method, while total carbohydrate and free amino acid content by Anthrone method and spectrophotometric method. The result showed highest protein contained in Tamarindus indica (103.98 ± 2.34 μg/mg) followed by Moringa olerifera (99.86 ± 2.32 μg/mg), Cicer arietinum (95.53 ± 2.78 μg/mg). The highest carbohydrate content was observed in the leaf of Amaranthus viridis (116.26 ± 2.33 μg/mg of plant tissue) followed by Marsilea vestita with carbohydrate content (82.35 ± 1.55 μg/mg), Chorchorus olitorius with carbohydrate content (50.46 ± 2.23 μg/mg), and highest free amino acid content was recorded in the leaves of (232.33 ± 2.05 μg/mg of plant tissue) followed by Brassica oleracea (204.94 ± 1.25 μg/mg), Cucurbita maxima (85.67 ± 2.35μg/mg). The study’s finding confirmed that wild leafy vegetables utilized by the special community of this area play a significant role in their livelihood as those vegetables contain higher nutrient level compared to conventional crops. As per the data reported, more than one million people of this region suffer from malnutrition so present study is an approach to overcome the health issue of people of this region in a sustainable manner

Effects of glutamic acid applications on the yield and growth parameters in garlic (Allium sativum L.) cultivation

Since exogenous amino acid applications to agricultural plants provide ready mineral nutrition for plants, they are widely used to enhance the yield and quality of crops as well as to strengthen resistance to environmental impacts. In the present study, the effects of L-Glutamic acid (GLU) (100, 200, 400, 800, and 1000 mg L-1) treatments on the growth parameters, bulb yield, chemical contents, and weight loss of Taşköprü garlic were analyzed. Given the findings, 800 GLU dose was found to have the highest values in shoot length and width, fresh weight, width, and length of the bulb, length and of large and small cloves, and yield per plot. On the other hand, the lowest results in total free amino acid, nitrate, polyphenol, ascorbic acid, and % ash amounts were obtained with 400 GLU, while the maximum leaf length and width was obtained with 1000 GLU dose. The first and third weight losses were obtained in 100 GLU and control groups and the second weight loss value obtained in all groups were higher than in the control. Considering all the data, the doses of 800 GLU and 400 GLU yielded the most positive effect on growth parameters, bulb yield, and weight loss measurements in garlic, whereas the lowest level of effect was observed in the control and 100 GLU groups. In conclusion, it can be stated that the foliar application of L-Glutamic acid in garlic cultivation might increase the yield and quality.

The effect of different pretreatment methods on jujube juice and lactic acid bacteria-fermented jujube juice

To obtain optimal juice-making methods, three pretreatment methods were selected to evaluate their effects on the quality characteristics of jujube juices before and after lactic acid bacteria fermentation. As a result, significant differences between all detected indicators were observed in fermented and unfermented jujube juices following different pretreatment methods. Jujube juices pretreated with hot water soaking (HS) had better color and higher levels of total sugar, reducing sugar and free amino acids than those pretreated with boiling water steeping (BS) and steam steaming (SS). Remarkably, similar tendencies were also found in the corresponding fermented jujube juices. In contrast, higher levels of total acids were found in all-jujube juices pretreated with BS. After lactic acid bacteria fermentation, however, all of the fermented jujube juices pretreated by the HS method displayed the highest total acid levels. As the major volatile components, the total levels of acids in the HS treatment were also significantly higher than those in the other two pretreatments. Sensory evaluation revealed that the fermented jujube juices after BS treatments showed relatively high acceptability among the panelists. These findings demonstrated valuable direction in improving the product quality of fermented jujube juice.

Effect of Koji on Flavor Compounds and Sensory Characteristics of Rice Shochu

Koji is an important starter for rice shochu brewing and influences the rice shochu quality. Consequently, we studied the impacts of koji on the flavor compounds and sensory characteristics of rice shochu using molds Aspergillus kawachii SICC 3.917 (A-K), Aspergillus oryzae SICC 3.79(A-O), Aspergillus Niger CICC 2372 (A-N), Rhizopus oryzae CICC 40260 (R-O), and the traditional starter Qu (control). The effects of koji on the aroma components, free amino acids (FAAs), and overall sensory aspects of rice shochu were studied. These findings indicated that koji significantly affected the rice shochu's quality. The content of total FAAs in rice shochu A-K (30.586 ± 0.944 mg/L) and A-O (29.919 ± 0.278 mg/L) was higher than others. The content of flavor compounds revealed that the aroma of rice shochu with various koji varied greatly from the smells of alcohols and esters. Shochu A-O had a higher concentration of aroma compounds and it exhibited a strong aroma and harmonious taste compared with the others. This research using taste compounds, FAAs, flavor intensity, and partial least squares regression (PLSR) showed that shochu A-O appeared to possess the best sensory qualities, with elevated concentrations of alcohols and sweet FAAs and lesser concentrations of sour FAAs. Therefore, the A-O mold is promising for the manufacture of rice shochu with excellent flavor and sensory characteristics.

Effects of roasting on the chemical compositions, color, aroma, microstructure, and the kinetics of changes in coffee pulp.

Roasting is a critical process that affects the quality attributes of coffee beans; however, how roasting conditions affect the physical, chemical, biological, and organoleptic changes of coffee pulp needs more research. In the present study, we investigated the effects of roasting temperatures and times on chemical compositions and quality attributes of coffee pulp. The results showed that the contents of total soluble sugar (TSS) and free amino acid (FAA) followed a temporal pattern of first increasing and then decreasing under the roasting temperatures between 100 and 160°C. Total phenolic content (TPC) and antioxidant activity of coffee pulp significantly (p<0.05) increased after roasting, reaching the maximum values of 83.09 mg gallic acid equivalent(GAE)/g and 360.45 µM 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid(Trolox)/g, respectively, when coffee pulp was roasted at 160°C for 18min. Drying rates of coffee pulp fitted the Logarithmic kinetic model, while color (L*, a*, and b*) changes and 5-caffeoylquinic acid degradation followed the first-order kinetic model. Electronic nose analysis showed that the main aroma compounds of the coffee pulp are sulfur-containing organics that were reduced with the extended roasting time. Scanning electronic microscopy analysis presented the loosened, shrunk, and cracked microstructure on the surface of the roasted coffee pulp, which might contribute to the increased TSS, FAA, TPC, and antioxidant activity of coffee pulp roasted under specific conditions. In conclusion, our research provides valuable information for preparing high-quality coffee pulp tea. PRACTICAL APPLICATION: This article investigates the effects of roasting on the chemical composition, color, flavor, microstructure, and the kinetics of changes in the moisture, color, and 5-caffeoylquinic acid (5-CQA) of the coffee pulp. We have found that high-temperature and short-time roasting helps retain the total phenolic contents, antioxidant activity, and aroma. The drying kinetic fits the Logarithmic model, and the changes in color and 5-CQA fit the first-order kinetic model. This study provides meaningful information for preparing coffee pulp tea with high-quality attributes and antioxidant activity.

Comparative study between triploid and diploid oysters (Crassostrea gigas) on non-volatile and volatile compounds

The quality of diploid oyster (crassostrea gigas) decreased significantly during the breeding period, which reflected the quality advantage of triploid oyster. However, there were few comparative studies on flavor quality characteristics between diploid and triploid oysters. This study compared the non-volatile compounds and volatile compounds between triploid and diploid oysters. These results showed that the percentage of eicosapentaenoic acid (EPA) in diploid oysters (18.68 ± 0.26%) was significantly higher than that in triploid oysters (16.16 ± 1.61%). The content of inosincacid (IMP) in diploid oysters (16.13 ± 0.03 mg/100 g) was significantly lower than that in triploid oysters (22.27 ± 0.41 mg/100 g). Adenosine monophosphate (AMP) content (364.08 ± 0.48 mg/100 g), succinic acid content (1244.51 ± 24.81 mg/100 g), and total free amino acid content (638.34 ± 17.32 mg/100 g) were significantly higher than those of triploid oysters (248.85 ± 2.32 mg/100 g, 420.99 ± 8.76 mg/100 g, 552.71 ± 17.32 mg/100 g, respectively). The main volatile compounds in diploid and triploid Pacific oysters were alcohols, aldehydes, ketones and esters. The volatile compounds content in triploid oysters were higher than those in diploid oysters. This study will provide basic data of Pacific oyster flavor and essential for the flavor pattern of seafood.

Double-Fermented Soybean Meal Totally Replaces Soybean Meal in Broiler Rations with Favorable Impact on Performance, Digestibility, Amino Acids Transporters and Meat Nutritional Value

Inclusion of microbial fermented soybean meal in broiler feed has induced advantageous outcomes for their performance and gastrointestinal health via exhibiting probiotic effects. In this study, soybean meal (SBM) was subjected to double-stage microbial fermentation utilizing functional metabolites of fungi and bacteria. In broiler diet, DFSBM replaced SBM by 0, 25, 50 and 100%. DFSBM was reported to have higher protein content and total essential, nonessential and free amino acids (increased by 3.67%, 12.81%, 10.10% and 5.88-fold, respectively, compared to SBM). Notably, phytase activity and lactic acid bacteria increased, while fiber, lipid and trypsin inhibitor contents were decreased by 14.05%, 38.24% and 72.80%, respectively, in a diet containing 100% DFSBM, compared to SBM. Improved growth performance and apparent nutrient digestibility, including phosphorus and calcium, and pancreatic digestive enzyme activities were observed in groups fed higher DFSBM levels. In addition, higher inclusion levels of DFSBM increased blood immune response (IgG, IgM, nitric oxide and lysozyme levels) and liver antioxidant status. Jejunal amino acids- and peptide transporter-encoding genes (LAT1, CAT-1, CAT-2, PepT-1 and PepT-2) were upregulated with increasing levels of DFSBM in the ration. Breast muscle crude protein, calcium and phosphorus retention were increased, especially at higher inclusion levels of DFSBM. Coliform bacteria load was significantly reduced, while lactic acid bacteria count in broiler intestines was increased with higher dietary levels of DFSBM. In conclusion, replacement of SBM with DFSBM positively impacted broiler chicken feed utilization and boosted chickens' amino acid transportation, in addition to improving the nutritional value of their breast meat.

Antixenosis by a resistant Musa cultivar to stem borer Odoiporus longicollis attack and expression of microsomal α-amylase by the pest

Banana pseudo-stem weevil (BPW) Odoiporus longicollis Olivier is a serious pest of Musa cultivars which completes its lifecycle as an internal parasite in the pseudo-stem of susceptible host plants. The larval stage of BPW is destructive and difficult to control as larvae are endophytic. Plantains (bananas), resistant to infestation by BPW, exhibited antixenosis against the larvae. Experimental maintenance of the larvae for 4 days in the live pseudo-stem of the resistant plantain resulted in the disruption of carbohydrate metabolism and imbalance of protein-free amino acid turnover. The pseudo-stem possesses three larvicides: stigmasterol-3-O-glucoside (SOG), sulfoquinovosyl diacylglycerol (SQDG), and betulinic acid (BA). Larvicides cause significant elevation in hemolymph protein and reduction in total free amino acids. Larvae treated with larvicides showed elevated activities of hexokinase, trehalase, and lactic acid dehydrogenase, which resulted in significant decrease of glucose and trehalose but sharp increase of lactic acid. Also, inhibition in the activity of glycogen phosphorylase caused significant increase of fat body glycogen in affected larvae. At LD20 concentration, toxicities by SOG, SQDG, and BA were similar but antixenosis by the resistant host plant was more severe due to the simultaneous action of three larvicides present in the resistant, live pseudo-stem. Disruption of carbohydrate metabolism and imbalance of protein-amino acid turnover due to toxicity by larvicides resulted in slow death of the larvae. The larval body responded against toxicity through the induction of the amy gene, which resulted in increased synthesis of α-amylase. The protein was sequenced as ID AHN 92452.2 with 496 amino acids, and the gene has 1491 nucleotides. Defense mechanisms by the larvae are not sufficient to resist antixenosis by the host plant. SOG, SQDG, and BA can be used synergistically as a larvicide for the control of BPW.

Modulation of structural and functional traits in facultative halophyte Salvadora oleoides Decne. For adaptability under hyper-arid and saline environments

Five differently adapted ecotypes were collected from (i) Jhang (JHG-mud flats near the Thal Desert margin), (ii) Rahim Yar Khan (RYK-sandy dunes of Cholistan Desert), (iii) Rajanpur (RJP-stony desert near the foothills), (iv) Lal Suhanra (LSR-hypersaline desert flat area), (v) Khewra mine (KHM-salt affected and sandstone mountain) during the peak of flowering season to unravel the underlying mechanism involved in their ecological success. The ecotypes from desertified regions possessed large leaves, root and shoot K+, total soluble proteins, chlorophyll (chl a, b, tchl, chl a/b and tchl/caro) and carotenoids, and thick cortical region, enlarged pith and its cells area in stems, and leaf thickness in terms of midrib and lamina thickness, epidermal and mesophyll thickness and large sized vascular bundles in leaves. In comparison the ecotypes of salt affected areas surpassed in growth attributes, ionic contents especially root and shoot Na+ and Ca2+, osmoprotectants (total free amino acids and soluble sugars) and antioxidants (SOD, CAT and POD). From this finding, we concluded that S. oleoides evolved multiple tolerance mechanisms at the structural and functional level to ensure survival under hyper-arid and saline environments, and can be explored later at a genetic level to surrogate in sensitive species.

The impact of Bee pollen addition on the quality characteristics of probiotic UF-soft cheese

This study aimed to evaluate adding bee pollen in different levels (0, 1.0, 2.0 and 3.0%) in the quality characteristics of probiotic UF-soft cheese. The samples were analyzed for physicochemical, biochemical, minerals (Iron, Manganese and Zinc), total phenolic, antioxidant activity, free fatty acids, free amino acids, textural, viability of ABT probiotic bacteria (Lactobacillus acidophilus LA-5, Streptococcus thermophiles and Bifidobacterium BB-12) and sensory properties of UF-soft cheese during the 30 days of storage. Bee pollen addition in UF-soft cheese significantly increased acidity, fat, protein, ash, WSN/TN%, TVFAs%, phenolic compounds (50% more), as well as the antioxidant activity. Moreover, bee pollen-added cheese were characterized by high contents of Fe, Mn, Zn, free fatty acids, free and total amino acids. Hardness, gumminess, and chewiness of cheese samples with bee pollen were higher than control cheese. The amount of total free amino acids in UF-soft cheese with bee pollen was almost two times higher in comparison with control cheese. Bee pollen addition caused an increase of unsaturated fatty acids, mainly omega-ω6 and omega-ω3 in UF-soft cheese. Tyrosine, glutamic, methionine, phenylalanine, isoleucine, and leucine acids were generally in high proportion in UF-soft cheese with bee pollen. The viability of ABT culture was significantly higher in bee pollen-added cheese than control cheese. Significant improvement was observed in sensory parameters (flavor and texture) for UF-soft cheese with 1.0 or 2.0 % bee pollen. It can be concluded that, probiotic UF-soft cheese with 1 or 2% bee pollen maybe proposed as new-functional cheese.

Tratamentos pré-germinativos em sementes de pitaya (Hylocereus spp.) para atenuação do estresse hídrico

ABSTRACT The use of mitigating agents to minimize the deleterious effects of water stress is a promising alternative for plant species, especially during germination and initial seedling development. Thus, the objective was to evaluate the effect of different pre-germination treatments as mitigating agents of water stress during germination and initial development of pitaya seedlings of the species Hylocereus undatus and H. costaricensis. The experiment was carried out in a completely randomized design, in a 2 x 6 factorial scheme, corresponding to two pitaya species and six pre-germination treatments (T1 = 0.0 MPa (control), T2 = -0.2 MPa (water stress); T3 = hydropriming + water stress; T4 = gibberellic acid + water stress; T5 = salicylic acid + water stress and T6 = thiamethoxan + water stress) with four replicates of 50 seeds. The variables analyzed were germination, germination speed index, shoot and primary root lengths, total dry mass, total soluble sugars and total free amino acids. The water potential of -0.2 MPa is limiting for germination and initial growth of H. costaricensis and H. undatus, with H. undatus being more tolerant to water stress in the germination phase. Pre-germination treatments with hydropriming, gibberellic acid, salicylic acid and thiamethoxan improve the physiological performance of H. costaricensis seeds, with gibberellic acid being the best attenuator of water stress. Gibberellic acid improves the physiological performance of H. undatus seeds under water deficit conditions.

Effects of microbial biostimulants (Trichoderma album and Bacillus megaterium) on growth, quality attributes, and yield of onion under field conditions

Microbial biostimulants (MBs) promote plant growth and stress tolerance in a sustainable manner. However, precise field trials of MBs are required in natural setting with a range of crop varieties to harness the benefits of biostimulants on crop yield improvement. This study investigated the effects of two MBs, Trichoderma album and Bacillus megaterium, on an onion cultivar's growth, nutritional qualities, antioxidant properties, and yield potentials under field conditions for two successive years. Before transplantation, onion bulbs were gelatin-coated with 2.0 and 4.0 g L−1 of each of the MB. Results revealed that MBs-pretreated onion plants exhibited better growth indices, photosynthetic pigment contents, and yield-attributing features like bulb weight than control plants. Nutraceutical analysis demonstrated that T. album-pretreated (by 2.0 g L−1) onion cultivar enhanced the level of K+ (by 105.79%), Ca2+ (by 37.77%), proline (by 34.21%), and total free amino acids (by 144.58%) in bulb tissues over the control plants. Intriguingly, the pretreatment with both T. album and B. megaterium (by 2.0 g L−1) increased the levels of total soluble carbohydrates (by 19.10 and 84.02%), as well as antioxidant properties, including increased activities of superoxide dismutase (by 58.52 and 31.34%), catalase (by 164.71 and 232%), ascorbate peroxidase (by 175.35 and 212.69%), and glutathione-S-transferase (by 31.99 and 9.34%) and improved the contents of ascorbic acid (by 19.1 and 44.05%), glutathione (by 6.22 and 33.82%), and total flavonoids (by 171.98 and 56.24%, respectively) in the bulb tissues than control plants. Although both MBs promoted the growth and nutraceutical qualities of onion bulbs, T. album pretreatment showed better effects than that of B. megaterium in the field settings. Based on the morphophysiological attributes and biochemical properties, a low dose (2.0 g L−1) was more effective than a high dose (4.0 g L−1) of T. album in promoting onion growth. Overall, the current research findings imply that T. album might be a potential MB in improving growth and quality attributes, and hence the productivity of onion cultivars under field circumstances.

The effect of seasonality on the biogenic amines, free amino acids, and physico-chemical composition of raw milk Fiore Sardo cheese produced in Sardinia (Italy)

The effect of seasonality on the content of biogenic amines (BA), compounds that could threaten food safety at a high level, were evaluated in Fiore Sardo, a typical artisanal raw sheep's milk cheese produced in Sardinia. The cheese samples collected from six farms, after four months of ripening, were manufactured from January to June. The relationship between the BA content, the free amino acid (FAA) concentration, and the physico-chemical composition (pH, a w , NaCl, humidity, and the fat and protein content) was considered. The FAA and BA contents were determined by HPLC-FL. The BA content and the other parameters analysed were significantly affected (p ≤ 0.000) by seasonality and the farm of origin. Despite the differences attributable to the producers, the seasonal variations of all the parameters considered followed the same trend. As the season changed, the level of total BA grew, reaching a mean content of 1402 ± 207 mg/kg in the samples produced in June, almost five times the mean value of those manufactured in January. The most represented biogenic amine was tyramine, followed by putrescine and cadaverine. Histamine was determined almost exclusively in some samples produced in the warmer months, while β-phenylethylamine and tryptamine were found in a low concentration or not detected. The winter products did not exceed the threshold of 900 mg/kg proposed for the total BA in food, while most of the samples manufactured in the hottest months exceeded this limit, posing a potential risk to consumers' health. The total FAA and BA content were correlated (p = 0.01), indicating that with the change of the season, proteolysis phenomena increased and made the precursor amino acids available for microbial decarboxylase activity. In addition, from January to June, the pH and fat levels grew, while those of a w , humidity and NaCl tended to decline. The study highlighted that as the season changed, the rise in temperature, probably combined with the increment of fat and decrement of NaCl content, could favour proteolysis phenomena and bacterial decarboxylase activity and, as a result, the escalation of BA production. Interventions in the production protocol to reduce the negative effect of seasonality on cheese safety are needed. In addition, in light of these results, it is possible to speculate that the rising temperature and the predicted lengthening of the warm season due to climate change, which also seems to affect the spring periods, could create the ideal conditions for the production of biogenic amines for an increasingly extended phase of the year.

Bitterness of Papaya Milk Is Related to Protein and Free Amino Acid Contents, with Phenylalanine and Tyrosine/Tryptophan Levels Being the Most Important

Papaya milk, a mixture of papaya pulp and dairy milk, is one of the most popular beverages in Taiwan. However, the enzymes present in papaya can cause accumulation of hydrophobic amino acids, resulting in a bitter taste of papaya milk. Thus, it is important to select papaya cultivars without the potential to form the bitter taste, but it is difficult to select these papaya cultivars using a sensory test. The purpose of this research was to investigate the relationship between the intensity of the bitterness with the contents of proteins and free amino acids. The results indicated that neither milk nor papaya alone tastes bitter. Heating the milk or the papaya before mixing and mixing only papaya latex with milk confirmed that an enzyme in papaya causes the bitter taste in papaya milk. The intensity of bitterness positively correlated with the contents of total soluble protein, free amino acids and the phenylalanine and tyrosine/tryptophan contents. Analyses using different papaya accessions in different seasons showed that tyrosine/tryptophan (r = 0.613***) and phenylalanine (r = 0.612***) correlate more strongly with bitterness intensity than the total soluble protein (r = 0.258*) or free amino acids (r = 0.38**). In this drink, milk provides the substrates to form the bitter substances, but the enzymes in the papaya are needed for the reaction to occur. The levels of the amino acids phenylalanine and tyrosine/tryptophan showed the highest correlation with the intensity of bitterness.

흑미죽의 품질 특성 및 항산화활성

This study evaluated the quality of black rice porridge by comparing changes in the proximate components and free amino acid contents. Three varieties of black rice were included in the study, and the factors were examined according to the variety and germination period. On the 3SUPrd/SUP day of germination, the protein content of Cheongpung Heukchal (CBR-3) black rice was 10.37 g/100 g, whereas the highest crude fat content at 3.44∼3.46 g/100 g was obtained on the 2SUPnd/SUP and 3SUPrd/SUP days of germination. The highest total free amino acid increase rate was 68.38∼588.24% obtained for Cheongpung Heukchal (CBR), followed by 39.87∼507.38% for Jindo No. 1 (JB1) and 33.03-542.84% for Jindo 2 (JB2), Thin rice gruel, half rice porridge, and whole rice porridge were prepared to determine the morphological characteristics of the porridege. The viscosity of germinated black rice porridge was 427∼977 cP, which was lower than the non-germinated porridge (620∼1313 cP). Evaluation of the antioxidant activity, revealed that the ABTS radical scavenging ability of non-germinated whole rice porridge was 76.34%, and germinated porridge was 81.38%. These values differed depending on the germinated form.