OBJECTIVE:To observe the effect of transcutaneous electrical acupoint stimulation (TEAS)combined with epidural analgesia on postpartum depression and to explore its underlying mechanism. METHODS:One hundred and twenty cases of full-term primiparous women with singleton pregnancy were selected from May 2018 to November 2018 in Jinzhong Maternal and Child Health Hospital. The parturients with labor analgesia requirement were randomly divided into the epidural group and the combination group, and the parturients without labor analgesia requirement were used as the control group, with 40 cases in each group. Patients in the control group did not receive labor analgesia and were treated according to the routine procedures of natural delivery; patients in the epidural group received epidural labor analgesia; patients in the combination group received TEAS at bilateral Hegu(LI4), Sanyinjiao(SP6) and Zusanli(ST36) (2 Hz/100 Hz, the current intensity is gradually increased from 15 mA, and the treatment was performed every 2 h, 20 min each time) combined with epidural labor analgesia. The visual analogue scale (VAS) scores were recorded when the uterine orifice opened to 3, 6, 8, 10 cm. Plasma glutamate was measured using high-performance liquid chromatography before analgesia, at the end of the third stage of labor and 42 days after delivery, and Edinburgh postnatal depression scale (EPDS) score was measured at 42 days after delivery. RESULTS:In comparison with the control group, the VAS score, EPDS score and the incidence of postpartum depression of the epidural group and the combination group were significantly lower(P<0.05), and the combination group had significant decrease than those in epidural group (P<0.05). Immediately before analgesia, there was no statistically significant difference in glutamate levels among the 3 groups (P>0.05). Compared with the control group, at the end of the third stage of labor and 42 days postpartum, the glutamate levels of the epidural group and the combination group were significantly reduced(P<0.05), and the combination group decreased more significantly than the epidural group (P<0.05). CONCLUSION:TEAS combined with epidural analgesia can reduce the incidence of postpartum depression, possibly by down-regulating plasma glutamate level and relieving of labor pain.

Lunasin has demonstrated antioxidative, anti-inflammatory, and chemopreventive properties. The objectives were to evaluate the concentration of lunasin in different lunasin-based commercial dietary supplements, to produce a lunasin-enriched soy extract (LESE) using a two-step pilot-plant-based ultrafiltration process, and to evaluate their biological potential in vitro. LESE was produced using 30 and 1 kDa membranes in a custom-made ultrafiltration skid. Lunasin was quantified in eight products and LESE. Lunasin concentrations of the lunasin-based products ranged from 9.2 ± 0.6 to 25.7 ± 1.1 mg lunasin/g protein. The LESE extract contained 58.2 mg lunasin/g protein, up to 6.3-fold higher lunasin enrichment than lunasin-based dietary supplements. Antioxidant capacity ranged from 121.5 mmol Trolox equivalents (TE)/g in Now® Kids to 354.4 mmol TE/g in LESE. Histone acetyltransferase (HAT) inhibition ranged from 5.3% on Soy Sentials® to 38.3% on synthetic lunasin. ORAC and lunasin concentrations were positively correlated, and HAT and lunasin concentrations were negatively correlated (p < 0.05). Melanoma B16-F10 and A375 cells treated with lunasin showed dose-dependent inhibitory potential (IC50 equivalent to 330 and 370 μM lunasin, respectively). Lunasin showed protein kinase B expression (57 ± 14%) compared to the control (100%) in B16-F10. Lunasin concentration found in commercial products and lunasin-enriched soy extract could exert benefits to consumers.

The conformational and functional changes of soybean protein after a hybrid extrusion-hydrolysis method were evaluated. Three extrusion temperatures (60, 80, and 100°C) were used prior to enzymatic hydrolysis. The hydrolysis degrees, molecular weight profiles, solubilities, surface hydrophobicities, sulphydryl contents, disulfide bound, water holding capacity, emulsion, and foam properties of the protein isolated from the enzyme-hydrolyzed extruded soybeans were analyzed. It shows that extrusion caused significant changes in the hydrophobicity, molecular weight distribution, solubility, surface hydrophobicity, emulsification activity, and stability of the protein. The increase of molecular weights could be attributed to the formation of protein aggregates during extrusion. Extrusion and enzymatic hydrolysis led to a sharp increase in the number of disulfide bonds with a decrease of the sulphydryl group. The water holding capacity and the solubility of protein increased with the increase of extrusion temperature and hydrolysis time. Extrusion improved the emulsifying activity but reduced the emulsifying stability of the recovered proteins. Extrusion improved the foam capacity but reduced the foam stability of the proteins. The data demonstrated that the extrusion-hydrolysis treatment significantly altered the conformational and functional properties of soybean protein, which may be further optimized for the development of new soy protein ingredient with desired functional properties.

The formation of free fatty acid (FFA) is an undesirable change during dry-grind corn ethanol fermentation because it negatively affects biodiesel transformation. The primary objective of this work was to determine where in the process FFA is generated using laboratory-scale simulation experiments. TLC and GC were used to quantify FFA in the extracted total lipids. Values obtained from FFA determination by titration were also compared with those obtained from TLC-GC. Results indicate that FFA generation is due to an incremental increase at each step in the process, particularly at the early slurrying and liquefaction stage, and also likely during the continuous backset. Furthermore, laboratory-based fermentations indicate that the oxidation of linoleic acid in the FFA fraction and possibly in the oil increased the FFA level determined using the titration method. Industrial oil samples collected were shown to be highly oxidized and this led to an overestimation of FFA by 15-24% using the titration method compared to TLC-GC due to the formation of a secondary oxidation product, acids. Such a discrepancy in FFA quantification and the level of lipid oxidation have not been seen in the literature.

A simultaneous texturization and extraction of phospholipids (STEP) technique was developed to extract phospholipids (PL) from liquid egg yolk. Three solvents, 100% butanol, 80% butanol, and 95% ethanol, were tested. All solvents can texturize the liquid yolk at the same time recover the lipid with greater than 90% total lipid recovery after five sequential extractions. It is shown that 100 and 80% butanol can extract the total lipid faster (i.e., more at the earlier stage) than the ethanol, and they are more effective in extracting total yolk lipids but with little preference for PL. On the contrary, 95% ethanol has high preference for PL than for neutral lipids. PL can be enriched to 80% purity directly from liquid yolk with a total PL yield of 78% using 95% ethanol under the first stage of the STEP conditions. Therefore, this 95% ethanol solvent has a great potential to process liquid yolk into a yolk lecithin concentrate, a neutral lipid‐rich fraction, and a defatted and texturized yolk protein. The uniqueness of this study is the simultaneous texturization and the strengthening of the yolk protein network that allows the extraction of lipids without the generation of the protein fines which could greatly reduce processing efficiency.Practical applications: The pharmaceutical, cosmetic, and infant formula industry can adopt this technology to more efficiently extract the highly nutritional and functional yolk lecithin or phospholipids from liquid yolk. Yolk drying is not necessary and ethanol is a desirable green solvent for yolk protein and lipid fractionation.Texturized egg yolk and total lipid extract at three stages of extraction using alcohol.

Two alcohols, ethanol and butanol, with different water contents were evaluated for phospholipids (PL) sequential extraction from drum dried egg yolk flakes. It showed that butanol was more effective in extracting total yolk lipids compared to ethanol, but the PL in the extract had the same concentration as in the original yolk total lipid. The use of aqueous ethanol of 95 and 75% resulted in lipid extracts with higher PL concentration during the initial stages of the sequential extraction. When ethanol was further diluted to a concentration of 55%, the solvent lost its PL extraction ability, and the total lipid recovery also decreased dramatically. When both the PL purity and recovery were considered, 75% ethanol was the most effective aqueous alcohol for PL extraction and enrichment from the yolk flakes. In the first stage of extraction using such a solvent, 67% of the total PL in the original yolk was recovered in a lipid fraction with a PL purity of 75%. This study identified the optimal ethanol concentration for PL extraction from dried egg yolk. With this information, the best solid:solvent ratio can be designed to extract and enrich the polar lipids from lipid-bearing materials with known moisture content using a renewable or “green” solvent, ethanol.

Chicken egg yolk is a concentrated source of phospholipids (PL). Extracting egg PL with high efficiency is vital to the availability and economics of this high-valued lipid product. In this study, two types of structured dry egg yolk materials, yolk flakes and pellets, were prepared. Two commonly used solvents, hexane and ethanol, were tested on the extraction of total yolk lipids including the PL. The PL fraction was obtained by the conventional cold acetone precipitation. The drum-dried yolk flakes were shown to be an ideal starting material for total lipid and PL extraction. Anhydrous ethanol can extract almost all the neutral lipids and PL with little change to the individual components of the native PL. A PL product with a purity of more than 90 % and a yield of 99 % can be prepared using this method.

Chicken egg contains a high level of phospholipids (PL) in the yolk. Recovering yolk total lipids and extracting egg PL with efficiency are important to the availability and utilization of these health-promoting lipid products. In this study, we prepared two structured dry egg yolk materials and used two common solvents to extract and concentrate the PL. We found that drum-dried flake-like yolk is an ideal starting material for lipid extraction. Anhydrous ethanol can extract almost all the neutral lipids and PL. PL with purity over 90% can be prepared by cold acetone precipitation from the total lipids.

The feasibility of using soy skim, a co-product of the aqueous processing of soybeans, in ethanol production from corn was evaluated. Specific growth rates were compared when Saccharomyces cerevisiae was grown in soy skim and peptone–yeast extract media supplemented with glucose. Such soy skim was proved to be a good nitrogen source for yeast growth. Next, fermentation of dry-ground corn to ethanol using soy skim as the media was simulated on 1.5-L scale. Replacing water with soy skim increased the initial ethanol production rates by 4–32% while final ethanol yield was about 39g/100g dry corn, similar to the result when water was used. Solid and protein contents in the finished beer increased with the addition of soy skim. Thus, replacing water in corn-ethanol fermentation with soy skim is feasible, and may improve the economics of both aqueous soybean processing and corn ethanol fermentation.

An aqueous enzymatic procedure for oleosome fractionation from 25 g of soy flour was developed in our laboratory. This fractionation procedure was evaluated with 75 kg using pilot plant equipment to evaluate the effect of the scale-up on the recovery, proximate composition, soybean storage protein profiles, and subcellular microstructure of oleosome fractions. The process included enzymatic hydrolysis, grinding, and centrifugation, respectively. Pilot-scale grinding and centrifugation of the slurry were accomplished with a Stephan® Microcut mill grinder and a three phase decanter. A blender and swinging bucket rotor were used for the laboratory-scale fractionation. The oleosome fractions recovered in the pilot plant were similar in oil and protein content to those obtained in the laboratory. The pilot-scale process resulted in a significantly higher oil yield of 93.40% as total oleosomes compared to that of 76.83% achieved in the laboratory. Urea–SDS gel electrophoresis of proteins extracted from the oleosomes and supernatant from the pilot-scale fractionation had similar profiles to those obtained in the laboratory. Electron microscopy verified that the structure of isolated oleosomes was virtually identical with that of in situ oleosomes. This work confirms that large-scale fractionation of oleosomes from full fat soybean flour can be accomplished.

Semipurified oleosomes were isolated on a pilot-plant scale using improved-process extraction conditions. The improved process consisted of continuous centrifugation in a three-phase decanter with recirculation of slurry until most of the oleosomes were recovered. Oleosome fractionation, oleosin identification, and isoflavone and saponin mass distributions and recoveries were investigated. The improved pilot-plant oleosome extraction process was achieved in 8 h. A total of 91%± 1% of soybean oil was recovered as intact oleosomes. The oil content of the aqueous supernatant and the residue fractions were low at 2% and 3%, respectively. The aqueous supernatant fraction contained 40% total soybean protein. About 76% of the proteins present in the oleosome fraction were soybean storage proteins. Washing the semipurified oleosomes with a 0.1 M Tris-HCl, pH 8.6 containing 0.4 M sucrose, and 0.5 M NaCl resulted in the recovery of the associated storage proteins. The recovery of these proteins in addition to the protein in aqueous supernatant accounted for 79% of the total soybean storage proteins fractionated by this process. Oleosins were detected at 17 and 18 kDa. Isoflavones and saponins partitioned into the oleosome, aqueous supernatant, and residue fractions at different ratios with the majority, about 82 and 63 mole%, respectively, in oleosome and aqueous supernatant fractions, making these fractions an attractive source for phytochemicals.

To investigate the ability of corn germ to withstand the fuel ethanol fermentation process without major damage to germ integrity and germ oil quality, five treatments were designed to explore degerming before fermentation (front-end) and after fermentation (tail-end), and the feasibility of breaking the kernel with minimum shear forces (wet-split). Germ from low-shear (wet-split) tail-end degerming maintained its integrity during the process. The wet-grind pretreatment caused 22% germ damage, and the subsequent fermentation caused 18% additional germ damage. The germ recovered after fermentation showed physical strength similar to that of those isolated by wet means before fermentation. The oils extracted from the tail-end germ fractions had the same low free fatty acid (FFA) content (2%) and similar low peroxide value (2 meq/kg) as those extracted at the front end. The good oil quality of the tail-end germ fraction was attributed to excellent germ integrity. The oil recovered after traditional dry-grind ethanol production was highly deteriorated, with 22% FFAs and 9 meq/kg peroxide value because the germ was broken into small pieces during dry grinding. So long as kernel-breakage or size-reduction pretreatments are conducted to retain intact germs or keep them in large pieces before fermentation, the germ can survive the cooking, starch hydrolysis, and yeast metabolism during the ethanol fermentation process. These findings lay a foundation for developing new degerming strategies where the germ can be isolated during or after fermentation, which could be easily integrated into the conventional dry-grind corn ethanol process.

In the dry-grind corn ethanol industry, horizontal decanter centrifuges are used to separate the whole stillage into wet grains and thin stillage. The wet grains mixed with condensed thin stillage are dried to form dried distiller’s grains with solubles (DDGS). In order to investigate the effect of different corn breaking treatments on increasing oil partitioning in thin stillage, a laboratory method is needed to simulate industrial decanting where a typical thin stillage is produced. The thin stillage obtained using a conventional laboratory centrifuge had much lower solids content and less than one-half of the dry-matter yield compared to the industry counterpart because the conventional laboratory centrifuge and industry decanter centrifuge have different separation mechanisms. By evaluating the properties of industrial thin stillage and the mechanism of industrial decanter centrifugation, a laboratory decanting device was designed and a decanting procedure, the multiple-wash centrifugal filtration (MWCF) method, was developed. This method involves multiple steps of filtration under centrifugal force after washing the solids with the liquid generated from the same mash. Four cycles of MWCF produced a thin stillage with similar solids content (7.3 vs. 7.2%), dry-matter yield (54.2 vs. 54.7%), and wet yield (83.3 vs. 80.6%) compared to industrial thin stillage. The presence of ethanol did not influence the laboratory decanting results, which indicates the application robustness of this laboratory thin stillage preparation method.

To study oil distribution in fermentation liquid and solids for the purpose of recovering oil from corn stillage by centrifugation, a low-shear single-screw extruder was used to treat corn for dry-grind ethanol fermentation. Five different treatments for corn were used, and their effects on ethanol fermentation, oil distribution, and oil extractability were studied. Extruded corn with different particles sizes had similar ethanol yields (33% based on corn) because the starch was equally gelatinized by extrusion. Pretreatment with larger particle size before extrusion tended to have higher free oil than pretreatment with smaller particle sizes, but the effect was not dramatic, which indicates that manipulating particle size has limited effect on oil distribution in the liquid. Autoclaved flaked corn had lower ethanol yield because autoclaving at 28% moisture did not fully gelatinize the starch. Addition of protease and cellulase significantly increased the ethanol yield by at least 4%. A significant amount of bound oil became more extractable after enzyme treatment. Such oil can be effectively extracted into liquid phase by using a surfactant. In general, oil tended to be strongly associated with the solids in the thin stillage. By enzymatic treatment, 70% oil distribution was achieved in the thin stillage, compared to the conventional fermentation, where only 50% oil goes into the liquid. It was also demonstrated that mass loss after fermentation can be used to accurately quantify ethanol yield.

The Kunitz trypsin inhibitor (KTI) and the Bowman-Birk inhibitor (BBI) of trypsin and chymotrypsin contain disulfide bonds. Glycinin, the major storage protein in soybeans also contains disulfide bonds. Treatment of soy white flour with a NADP-thioredoxin system (NTS) effectively reduced disulfide bonds in soy flour and increased protein digestibility by trypsin and pancreatin as measured by the pH stat method. Treatment of soy flour with NTS increased the digestibility compared to soy white flour by 29.3 and 60.6% for trypsin and pancreatin, respectively. NTS-treated soy flour had similar digestibility by trypsin to autoclaved soy flour and casein, but digestibility by pancreatin was less than autoclaved soy flour and casein. The degree of reduction by NTS was highly correlated to the degree of hydrolysis (DH) by trypsin (R(2) = 0.93) and pancreatin (R(2) = 0.99). The DH of NTS-treated soy flour by trypsin is reflective of both inactivation of trypsin inhibitors and overall protein digestibility while pancreatin hydrolysis is reflective of only overall protein digestibility.

Two Escherichia coli O157:H7 strains, SEA 13 B88 gfp 73ec and B6-914 gfp 90ec, together with two bacteria, three yeasts, and two molds that were randomly selected from a collection of microorganisms found on apples or in apple cider, were inoculated into apple cider and subjected to electron beam irradiation at several doses between 0.0 and 2.3 kGy at the Iowa State University Linear Accelerator Facility. The D-values for the E. coli O157:H7 strains ranged between 0.25 and 0.34 kGy; the D-values for most of the normal flora from apples ranged between 0.24 and 0.59 kGy. By taking into account possible variations in treatment conditions, it was calculated that irradiation at 2.47 kGy should achieve a 5-log reduction of E. coli O157:H7 in apple cider at the 95% confidence level. Naturally occurring yeasts might survive such irradiation treatment.

Serious outbreaks of illness in 1996 and 1999 linked to contamination of apple cider by E. coli O157:H7 have contributed to intense public concern regarding the safety of fresh apple cider. In response to this concern, the Food and Drug Administration (FDA) has proposed more stringent regulations on the production of apple cider including a requirement to reduce microbial contaminants by 5 logs (Terpstra, 1997). Currently, FDA requires a warning statement on all fruit and vegetable juice products that have not been pasteurized (FDA, 1998). The safety concerns associated with fresh apple cider have contributed to a need to evaluate new approaches to cider processing to provide a safe product without sacrificing quality (Terpstra, 1997).

Processing treatments used to produce a microbiologically "safe" apple cider were evaluated to determine the impact of these treatments on the overall flavor characteristics. Apple cider with (0.1%) and without (0%) potassium sorbate was subjected to four processing treatments: untreated, irradiated at 2 kGy, irradiated at 4 kGy, and pasteurized. Volatile flavor compounds were isolated from the cider using solid-phase microextraction methods with gas chromatographic analysis. A trained descriptive analysis panel evaluated sensory attributes. The effects of the processing treatment were dependent on the presence of sorbate in the apple cider. Irradiation treatments resulted in a decrease in the content of esters characteristic of apple flavor and an increase in the content of alcohols and aldehydes formed through lipid oxidation reactions. The presence of sorbate reduced the effects of the irradiation treatments on these volatile flavor compounds. Sensory panelists, however, detected higher intensities of undesirable flavor attributes, including "cardboard flavor", and lower intensities of the desirable "apple flavor" in irradiated cider with added sorbate.