Sources of acid insoluble ash as marker of corn digestibility in broilers

The objective was to evaluate three sources of acid insoluble ash (AIA) (celite, kaolin, and sand), as indicators, to determine the apparent metabolizable energy of corn on a natural matter (AME) basis, dry matter digestibility coefficient (DMDC), and crude protein digestibility coefficient (CPDC) using total and partial excreta collection methods. Two hundred and ten Ross broiler chicks of 18 to 27 days of age were used. Broilers were adapted to experimental the diet for four days, and excreta were collected for 5 days. A reference diet (RD) based on corn and soybean meal was prepared to meet the nutritional requirements of the birds. A test diet was prepared with 40% replacement of RD with corn. The formulated diets were: D1, 99% Reference diet + 1% celite; D2, 59.4% RD + 39.6 % corn + 1% celite; D3, 99% Reference diet + 1% kaolin; D4, 59.4% RD + 39.6 % corn + 1% kaolin; D5, 99% Reference diet + 1% sand; D6, 59.4% RD + 39.6 % corn + 1% sand. The treatments were distributed in a completely randomized design, with six diets and five replicates of seven birds each in a 2x3 factorial arrangement. There were significant interactions for all variables investigated. It was observed that the AME and DMDC values of corn were similar in the two methods of collection, and PDC values using kaolin and celite makers were similar. However, the AME and CPDC of corn using sand with partial collection method were underestimated by 17.70 and 15.53%, respectively compared to those with the total collection method. The AME values of corn with the collection methods using celite and, the DMDC using celite and sand were significantly different. It was observed that the DMDC using celite and sand provided significantly lower values (4.67 and 5.15%), respectively, and the AME using celite was 2.86% lower than that obtained by total collection. To determine the EMA, DMDC, and CPDC in broilers, it is more efficient to use celiteTM and kaolin as markers with partial collection of excreta. Sand should not be used with partial excreta collection method, because it provides lower values of AME and CPDC compared to with total excreta collection method.

Impact of Raw, Roasted and Dehulled Chickpea Flours on Technological and Nutritional Characteristics of Gluten-Free Bread

The main objective of this study was to develop a healthy rice-based gluten-free bread by using raw, roasted, or dehulled chickpea flours. All breads containing chickpea flours showed a darker crust and were characterized by an alveolar (porosity 41.5–51.4%) and soft crumb (hardness 5.5-14.1 N). Roasted chickpea flour bread exhibited the highest specific volume, the softest crumb, and the slowest staling rate. Enriching rice-based breads with the chickpea flours resulted in increased protein (from 9.72 to 12.03–13.21 g/100 g dm), ash (from 2.01 to 2.45–2.78 g/100 g dm), fat (from 1.61 to 4.58–5.86 g/100 g), and total phenolic contents (from 49.36 up to 80.52 mg GAE/100 g dm), and in reduced (~10–14% and 13.7–17%, respectively) available starch levels and rapidly digestible starch compared to rice bread. Breads with roasted chickpea flour also showed the highest in vitro protein digestibility. The results of this study indicated that the enrichment of rice-based gluten-free breads with chickpea flours improved the technological and nutritional quality of the breads differently according to the processed chickpea flour used, also allowing recovery of a waste product.

Genome-wide high-throughput signal peptide screening via plasmid pUC256E improves protease secretion in Lactiplantibacillus plantarum and Pediococcus acidilactici

Background Proteases catalyze the hydrolysis of peptide bonds of proteins, thereby improving dietary protein digestibility, nutrient availability, as well as flavor and texture of fermented food and feed products. The lactobacilli Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) and Pediococcus acidilactici are widely used in food and feed fermentations due to their broad metabolic capabilities and safe use. However, extracellular protease activity in these two species is low. Here, we optimized protease expression and secretion in L. plantarum and P. acidilactici via a genetic engineering strategy. Results To this end, we first developed a versatile and stable plasmid, pUC256E, which can propagate in both L. plantarum and P. acidilactici. We then confirmed expression and secretion of protease PepG1 as a functional enzyme in both strains with the aid of the previously described L. plantarum-derived signal peptide LP_0373. To further increase secretion of PepG1, we carried out a genome-wide experimental screening of signal peptide functionality. A total of 155 predicted signal peptides originating from L. plantarum and 110 predicted signal peptides from P. acidilactici were expressed and screened for extracellular proteolytic activity in the two different strains, respectively. We identified 12 L. plantarum signal peptides and eight P. acidilactici signal peptides that resulted in improved yield of secreted PepG1. No significant correlation was found between signal peptide sequence properties and its performance with PepG1. Conclusion The vector developed here provides a powerful tool for rapid experimental screening of signal peptides in both L. plantarum and P. acidilactici. Moreover, the set of novel signal peptides identified was widely distributed across strains of the same species and even across some closely related species. This indicates their potential applicability also for the secretion of other proteins of interest in other L. plantarum or P. acidilactici host strains. Our findings demonstrate that screening a library of homologous signal peptides is an attractive strategy to identify the optimal signal peptide for the target protein, resulting in improved protein export.

Comparative effects of high pressure processing and heat treatment on in vitro digestibility of pea protein and starch

The effects of high-pressure processing (HPP) and heat treatment on the digestibility of protein and starch in pea protein concentrate (PPC) were investigated. Samples of PPC with 5% (5 P) and 15% (15 P) protein were treated by HPP (600 MPa/5 °C/4 min) or heat (95 °C/15 min) and their in vitro static and dynamic digestibility were compared to untreated controls. HPP-treated PPC underwent a greater degree of proteolysis and showed different peptide patterns after static gastric digestion compared to untreated and heat-treated PPC. Differences in protein digestibility among treatments during dynamic digestion were only significant (p < 0.05) during the first 20 min of jejunal, ileal, and total digestion for 5 P, and during the first 60 min of ileal digestion for 15 P. Neither static nor dynamic starch digestibility were dependent on treatment. HPP did not reduce trypsin inhibitor activity, whereas heat treatment reduced it by ~70%. HPP-induced structural modifications of proteins and starch did not affect their overall in vitro digestibility but enhanced gastric proteolysis.

Effects of Microwaves, Ultrasonication, and Thermosonication on the Secondary Structure and Digestibility of Bovine Milk Protein

Cow’s milk is considered an excellent protein source. However, the digestibility of milk proteins needs to be improved. This study aimed to evaluate the relationship between the functional properties of milk proteins and their structure upon microwave, ultrasound, and thermosonication treatments. The protein content, digestibility, and secondary-structure changes of milk proteins were determined. The results demonstrated that almost 35% of the proteins in the untreated samples had a α-helix structure and approximately 29% a β-sheet and turns structure. Regarding the untreated samples, the three treatments increased the α-helices and correspondingly decreased the β-sheets and turns. Moreover, the highest milk protein digestibility was observed for the ultrasound-treated samples (90.20–94.41%), followed by the microwave-treated samples (72.56–93.4%), whereas thermosonication resulted in a lower digestibility (68.76–78.81%). The milk protein content was reduced as the microwave processing time and the temperature increased. The final milk protein available in the sample was lower when microwave processing was conducted at 75 °C and 90 °C compared to 60 °C, whereas the ultrasound treatment significantly improved the protein content, and no particular trend was observed for the thermosonicated samples. Thus, ultrasound processing shows a potential application in improving the protein quality of cow’s milk.

Penggunaan Cairan Ekstrak Isi Gizzard dan Duodenum Ayam pada Pengukuran Kecernaan In Vitro Daun Turi (Sesbania grandiflora)

The aim of this study was to examine the use of Gizzard Contents Extracts (GCE) and Duodenum Contents Extracts (DCE) of Chicken on In Vitro digestibility measurements of Turi Leaves (Sesbania grandiflora). The study was designed using a One-way Classification of Completely Randomized Design (CRD) with 4 treatments. Each treatment was repeated three times. Types of treatment in the form of using GCE and DCE, including: (1) control treatments (without GCE or DCE), (2) GCE, (3) DCE, and (4) a mixture of GCE and DCE. The observed variables were Coefficient of Dry Matter Digestibility (CDMD), Coefficient of Organic Matter Digestibility (COMD), and Coefficient of Soluble Protein Digestibility (CSPD). The results showed that the addition of GCE, DCE, and a mixture of GCE and DCE could not increase the CDMD, COMD, and CSPD of Turi Leaves compared to the control treatment. Keywords: Duodenal contents extract; Gizzard content extract; In vitro digestibility; Turi leaves. Abstrak Penelitian bertujuan untuk mengkaji penggunaan cairan ekstrak isi gizzard (CEIZ) dan duodenum (CEID) ayam pada pengukuran kecernaan in vitro daun turi. Penelitian dirancang menggunakan Rancangan Acak Lengkap (RAL) pola searah dengan 4 perlakuan. Masing-masing perlakuan diulang tiga kali. Macam perlakuan berupa penggunaan penggunaan CEIZ dan CEID ayam, meliputi perlakuan kontrol (tanpa CEIZ maupun CEID), CEIZ, CEID, dan campuran CEIZ dan CEID. Variabel pengamatan berupa koefisien cerna bahan kering (KCBK), koefisien cerna bahan organic (KCBO), dan koefisien cerna protein terlarut (KCPT). Hasil penelitian menunjukkan bahwa perlakuan penambahan cairan ekstrak isi gizzard, duodenum dan campuran keduanya tidak dapat meningkatkan KCBK, KCBO, dan KCPT daun turi dibandingkan dengan perlakuan control. Kata kunci: Cairan ekstrak isi duodenum; Cairan ekstrak isi gizzard; Daun turi; Kecernaan in vitro.

EFFECTS OF THE INCLUSION OF STAR GOOSEBERRY DRIED LEAF EXTRACT IN RATION ON EGG ORGANOLEPTIC VALUES OF LOCAL DUCK

Duck egg is known to have an unpleasant fishy odor which often becomes a factor reducing its acceptance in public. This odor is resulted from lipid oxidation which can be avoided by using an antioxidant. This study was aimed at assessing the effects of the inclusion of star gooseberry (Sauropus androgynus) dried leaf extract in ration on egg organoleptic quality of local duck. The study was conducted in a completely randomized design with 4 treatments and 4 replicates. Sensory test by 60 semi-trained panelists and hedonic quality and hedonic tests were conducted. Data were subjected to a Kruskal-Wallis test. Results showed that treatments gave significant effects (P <0.05) on aroma (hedonic), yolk color, and aroma (hedonic quality). It was concluded that the inclusion of star gooseberry dried leaf extract by 1,5% in ration improved the quality of egg yolk color, egg aroma, and consumers’ preference. A further study on the effects of DSGLE on meat quality and protein digestibility in ducks was recommended.