Arsenic Toxicity-Induced Physiological and Metabolic Changes in the Shoots of Pteris cretica and Spinacia oleracea

Arsenic is a ubiquitous toxic element that can be accumulated into plant parts. The present study investigated the response of Pteris cretica and Spinacia oleracea to As treatment through the analysis of selected physiological and metabolic parameters. Plants were grown in pots in As(V) spiked soil (20 and 100 mg/kg). Plants’ physiological condition was estimated through the determination of elements, gas-exchange parameters, chlorophyll fluorescence, water potential, photosynthetic pigments, and free amino acid content. The results confirmed differing As accumulation in plants, as well as in shoots and roots, which indicated that P. cretica is an As-hyperaccumulator and that S. oleracea is an As-root excluder. Variations in physiological and metabolic parameters were observed among As treatments. Overall, the results revealed a significant effect of 100 mg/kg As treatment on the analysed parameters. In both plants, this treatment affected growth, N, Mg, S, Mn, and Zn content, as well as net photosynthetic rate, chlorophyll fluorescence, and total free amino acid content. In conclusion, the results reflect the similarity between P. cretica and S. oleracea in some aspects of plants’ response to As treatment, while physiological and metabolic parameter changes related to As treatments indicate the higher sensitivity of S. oleracea.

Complete Replacement of Nitrite With a Lactobacillus fermentum on the Quality and Safety of Chinese Fermented Sausages

This study investigated the positive effects of complete replacement of nitrite with a Lactobacillus fermentum on the quality and safety of Chinese fermented sausages, and evaluated the risk of this strain. The effects of the strain on pH, color, nitrite, thiobarbituric acid reactive substances (TBARS), total volatile basenitrogen (TVB-N), metmyoglobin (Met-Mb), biological amines, free amino acid content, and sensory index have been studied. The results revealed that the strain reduced the pH of the sausages, which reduced the risk of food-borne pathogens, and accelerated the acidification and gelation process. The inoculation of the strain produced pink color similar to 50 mg/kg nitrite, significantly reducing the residual risk of nitrite in the sausages. In addition, the strain effectively improved quality and nutrition of the sausages through preventing fat oxidation, protein decomposition, and myoglobin oxidation and increasing free amino acid content. The harmful biogenic amines species of the treated sample were reduced, although the tyramine contents were higher than the control, and the contents of the two groups were all far below the specified limit (800 mg/kg). The sensory analysis showed that the strain enhanced the taste, flavor, sourness, and overall acceptability of the sample sausages. Therefore, replacing nitrite completely with the strain L. fermentum could be a potential strategy to produce healthier and safer acceptable sausages through decreasing the risk of nitrite and improving nutrition and quality of the sausages.

Targeting the Nutritional Value of Proteins From Legumes By-Products Through Mild Extraction Technologies

Legumes have been known for centuries for their good nutritional properties. Unfortunately, during processing, from 5 to 25% of this production is wasted, generating by-products that can still be a rich source of useful compounds, such as proteins, which can still be used in food and feed formulations. The choice of the extraction technique is important to preserve the nutritional value of proteins since drastic conditions of pH and/or temperature could damage them. In this work, two mild extraction techniques (direct assisted extraction—DAE and enzymatic assisted extraction—EAE) were applied for protein extraction from legume by-products obtained from agro-industrial processes. The quality of proteins was evaluated considering protein integrity [SDS-PAGE, degree of hydrolysis (DH), free amino acid content, racemization degree] and nutritional features [amino acid score (AAS), digestibility]. Direct assisted extraction is the technique that has best preserved protein integrity (1–5% DH and free amino acid content <1%), The digestibility of proteins extracted with EAE is higher (no protein bands detected in SDS-PAGE) than with the one of DAE extracts, making this technique particularly suitable for those food and feed formulation were a high digestibility of proteins is required.

Impacts of different blanching pretreatments on the quality of dried potato chips and fried potato crisps undergoing heat pump drying

Hot water blanching (WB) and steam blanching (SB) have been noted to improve the quality of potato chips. In this work, the possibility of steam blanching assisted with ultrasound treatment (SUB) to enhance the quality of dried potato chips and fried potato crisps was investigated. Compared to WB and SB groups, dried potato chips of SUB groups showed lower shrinkage ratio (78.46%), higher rehydration capability (3.93:1), and lower moisture content (0.08 g/g). Meanwhile, fried potato crisps of SUB groups displayed lower hardness (1965.70 g) and oil content (12.0%). The low reducing sugar content (0.42%) and free amino acid content (6.10 mg/g) in SUB dried potato slices could explain for the higher L * value, lower a * and ΔE values of SUB fried potato crisps. Additionally, sensory evaluation results confirmed above obtained consequences. Overall, SUB could improve the quality of fried potato crisps further in comparison with WB and SB.

The Free-Amino-Acid Content in Six Potatoes Cultivars through Storage

Potatoes of six cultivars (Solanum tuberosum L.) with red, purple, and yellow flesh were stored at 2 and 5 °C for 3 and 6 months, and the influence of these factors on the content of free amino acids was determined. The potato cultivar and storage time had the greatest impact on the free amino acid content. The tubers of red-fleshed (Rote Emma) and purple-fleshed (Blue Congo) potatoes contained over 28 mg/g DM of free amino acids, and the Blaue Annelise cultivar with purple flesh had over 18 mg/g DM. After 6 months, the highest increase in their content (by 36%) was recorded in tubers of the Fresco cultivar (yellow-fleshed). In the analysed potatoes, the content of alanine, proline, serine, γ-aminobutyric acid, and α-aminoadipic acid increased, while that of asparagine, aspartic acid, and glutamine decreased. Asparagine decreased to the greatest extent in “Blaue Annelise” potatoes (by 24%) and that of glutamine in tubers of Rote Emma and Vineta by 18%.

Evaluation of seed amino acid content and its correlation network analysis in wild soybean (Glycine soja) germplasm in Japan

Wild soybean (Glycine soja) is a valuable genetic resource for soybean improvement. Seed composition profiles provide beneficial information for the effective conservation and utilization of wild soybeans. Therefore, this study aimed to assess the variation in free amino acid abundance in the seeds of wild soybean germplasm collected in Japan. The free amino acid content in the seeds from 316 accessions of wild soybean ranged from 0.965 to 5.987 mg/g seed dry weight (DW), representing a 6.2-fold difference. Three amino acids had the highest coefficient of variation (CV): asparagine (1.15), histidine (0.95) and glutamine (0.94). Arginine (0.775 mg/g DW) was the predominant amino acid in wild soybean seeds, whereas the least abundant seed amino acid was glutamine (0.008 mg/g DW). A correlation network revealed significant positive relationships among most amino acids. Wild soybean seeds from different regions of origin had significantly different levels of several amino acids. In addition, a significant correlation between latitude and longitude of the collection sites and the total free amino acid content of seeds was observed. Our study reports diverse phenotypic data on the free amino acid content in seeds of wild soybean resources collected from throughout Japan. This information will be useful in conservation programmes for Japanese wild soybean and for the selection of accessions with favourable characteristics in future legume crop improvement efforts.

Effect of High Hydrostatic Pressure Processing on the Chemical Characteristics of Different Lamb Cuts

The non-thermal high-pressure processing (HPP) technique has been used to increase the shelf life of food without compromising their nutritional and sensory qualities. This study aims to explore the potential application of HPP on New Zealand lamb meat. In this study, the effect of HPP, at different pressure treatments (200–600 MPa) on eight different lamb meat cuts in terms of lipid oxidation, fatty acid and free amino acid content were investigated. In general treatments between 400 and 600 MPa resulted in higher oxidation values in eye of loin, flat, heel, and tenderloin cuts. Saturated and monounsaturated fatty acid content were significantly lower with HPP treatment of almost all cuts (except rump and heel cuts) at all pressures. Polyunsaturated fatty acid content was significantly lower in HPP-treated inside, knuckle, and tenderloin cuts at 600 MPa compared to control. Nine essential free amino acids (valine, leucine, isoleucine, methionine, phenylalanine, lysine, histidine, tyrosine and tryptophan), and eight non-essential free amino acids (alanine, glycine, threonine, serine, proline, aspartic acid, glutamic acids and ornithine) were identified in the lamb cuts. HPP increased the total free amino acid composition significantly compared to control at all pressures for almost all cuts except the inside and eye of loin cuts. This study suggests that higher pressure treatments (i.e., 400 and 600 MPa) resulted in higher TBARS oxidation levels. Additionally, significant decreases in saturated and monounsaturated fatty acids and increase free amino acid content were observed in the majority of HPP-treated samples compared to control.

Role of amylase and protease in germinatingSterculia urens Roxb

The present study explains the levels of proteins and enzymes like proteases and amylases associated with the breakdown of proteins and carbohydrates during various stages (0 day to 15th day) of seed germination of Sterculia urens Roxb.. Maximum protease activity (1.12 units/mg of protein) and amylase activity was observed on 12thday of seed germination (34 units/mg of protein) and decreased thereafter. Highest protein content was observed at initial stage of seed germination and decreased thereafter. Increased proteolytic activity and amylase activity proportionately increases free amino acid content and sugars that promotes the seedlings growth and development. Bangladesh J. Sci. Ind. Res.55(2), 107-112, 2020

Effect of different post-harvest treatments on free amino acid content in Fucus vesiculosus

The effect of different post-harvest treatments (fresh, freezing and air-drying) and storage duration on free amino acid (FAA) content of brown seaweed Fucus vesiculosus were studied. The FAA profile of thalli algae was studied every 3 months over 1 year. The FAA were extracted in ethanol/water (70: 30) solution, purified by ion exchange chromatography, derivatized and determined using hight-performance liquid chromatography. Free amino acid profile was significantly (p<0.001) different among the fresh, freezing and air-drying seaweeds. Long-term storage of seaweeds for 12 months in both dried and frozen form contributed to increased levels of free amino acids. The total free amino acid content increased from 285.80 mg/100 g dry matter of fresh seaweeds to 597.38 mg/100 g dry matter of dried seaweeds and to 473.84 mg/100 g dry matter of the frozen form. The total content of essential amino acids increased from 49.65 mg/100 g dry matter in fresh seaweeds to 130.45 mg/100 g dry matter of dried seaweeds and to 106.70 mg/100 g dry matter of frozen seaweeds. The content of glutamic acid responsible for the taste increased from 132.36 mg/100 g dry matter of fresh seaweeds to 169.50 mg/100 g dry matter of dried seaweeds, and to 242.00 mg/100 g dry matter of frozen seaweeds. Thus, the long-term storage of dried and frozen seaweeds contributes to the improvement of their qualities.