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Food and agricultural waste contribute to resource depletion, waste accumulation and climate change. Chicken egg and almond hull waste streams have favourable nutritional profiles but are underexplored for environmentally friendly livestock feed applications. We report extrusion processing and nutritional analysis of blends containing liquid egg and almond hulls. Compositions showed favourable processing, protein content comparable to grain silages and relatively low neutral detergent fibre. No differences in crude protein or fat were observed between Hard-variety and Nonpareil almond hull compositions. Hard-variety compositions contained nearly twice the crude fibre as Nonpareil mixtures. Crude protein increased from 9.3 to 13.8% with 30–50% egg content. Bacterial proliferation in extrudates was minimal due to the low water activity (aw = 0.80–0.82 in 30% egg formulations). No Salmonella or mycotoxins (aflatoxin, vomitoxin, zearalenone) were detected. This work provides a method for repurposing high moisture, high protein food waste into animal feed using abundant, low-cost almond crop residues and demonstrates the feasibility of creating an animal feed from liquid egg waste and almond hulls. [ABSTRACT FROM AUTHOR]

Controlling postprandial hyperglycemia is considered as a viable prophylactic treatment for type 2 diabetes mellitus. A major strategy in decreasing postprandial glucose involves inhibition of the carbohydrate-hydrolyzing enzymes, α-amylase and α-glucosidase. The aim of this study was to evaluate the hypoglycemic potential of almond hull extract in vitro and in vivo. The in vitro results showed that, among the 0 %, 30 %, 50 % and 80 % ethanol extracts of almond hull, the 50 % ethanol extracts demonstrated the most significant inhibition of digestive enzymes. With in vivo tests, the blood glucose concentration in the control rats increased sharply near the peak glucose level in 15 min, while the peak glucose level of rats loading the almond hull extract occurred in 30 min. Therefore, almond hull extract can reduce postprandial blood glucose levels and delay the time to peak by about 15 min, providing a sustained and gradual release of energy.

This study aimed to evaluate the effect of chemical treatments of almond hulls (AH) issued from two mediterranean countries (Tunisia and Palestine) on chemical composition, gas production (GP), methane (CH4), and in vitro ruminal fermentation. Treatments included AH untreated, AH supplemented with PEG, treated with NaOH, and with urea for 40 d. Significant (P

Simple Summary: Almond hull (AH) is a by-product of almond production that can be used in ruminant feeding, but their composition is variable and needs further characterization. We observed that there were significant differences in chemical composition and nutritional value of samples of AH from two varieties, with AH from Guara variety having more energy and protein than those from Soleta variety in samples collected in two different almond campaigns in the South of Spain. Moreover, harvesting year affected the chemical composition and nutritive value of AH, making necessary their chemical analysis before being used as feed in the practice. In addition, we conducted in vitro trials to investigate the effects of including increasing amounts of AH in diets for dairy ruminants on diet degradability and methane production. Methane is a greenhouse gas with high warming potential that is produced during feed fermentation in the rumen. The results indicate that dried AH can replace up to 16% of conventional feed ingredients in diets for dairy ruminants, but methane production was not reduced. In conclusion, the tested AH can be used as alternative feed for ruminants, although this by-product does not contain antimethanogenic compounds. Almond hulls (AH) are frequently used in dairy ruminant feeding, but information on variability of their nutritive value and their potential effects on CH4 production is still scarce. The influence of almond variety (Guara vs. Soleta) on chemical composition and energy value of AH was investigated using 10 samples per variety collected in 2 consecutive years. Guara-AH had greater (p ≤ 0.015) ash, protein, and fat content, but lower (p ≤ 0.001) fiber than Soleta-AH. The metabolizable energy content estimated from chemical composition and in vitro gas production was 8.5% greater for Guara than for Soleta samples. Harvesting year significantly affected most of the chemical fractions. The in vitro ruminal fermentation of diets for dairy ruminants including increasing amounts of dried AH (8, 16 and 24% of the total diet; fresh matter basis) indicated that AH can be included up to 16% of the diet, partially substituting corn, wheat bran and sugar beet pulp without detrimental effects on in vitro volatile fatty acid (VFA) production. In contrast, when AH replaced alfalfa hay and corn, VFA production was reduced at all levels of AH inclusion. No antimethanogenic effects of AH were detected in the in vitro incubations. [ABSTRACT FROM AUTHOR]

Almond processing generates a high quantity of by-products, presenting the untapped potential for alternative applications and improved sustainability in production. This study aimed to evaluate whether the incorporation of almond by-products (hulls/shells) can improve the biochemical characteristics of green bean pods when used as an alternative to traditional growing media in green bean plants. Four substrates were prepared: the Control substrate (C): 70% peat + 30% perlite; substrate (AS): 70% peat + 30% shells; substrate (AH): 70% peat + 30% perlite + 1 cm hulls as mulch; substrate (MIX): 70% peat + 15% shells + 15% hulls. Plants were grown in each of these substrates and subjected to two irrigation levels, 100% and 50% of their water-holding capacity. Biochemical parameters (photosynthetic pigments, total phenolics, flavonoids, ortho-diphenols, soluble proteins, antioxidant capacity) and color were evaluated in the harvested pods. Results showed that pods from plants growing in AH substrate presented statistically significant higher values in their total phenolic content, while AS and MIX substrates did not reveal significant benefits. Summarily, this study highlights the potential of almond hulls as a promising medium for green bean cultivation, particularly when employed as mulch. Further research is recommended to gain a more comprehensive understanding of the application of almond by-products as natural fertilizers/mulch. [ABSTRACT FROM AUTHOR]

Almond hulls and shells are a by-product of almond production that can be incorporated as a feed ingredient in beef cattle diets. Three experiments were conducted to determine the effects of hammermill screen size on almond hull and shell bulk density and inclusion of ground or non-ground almond hulls and shells in limit-fed growing diets on growth performance, diet digestibility, and ruminal fermentation characteristics of beef cattle. In experiment 1, almond hulls and shells were ground with a laboratory-scale hammermill using no screen, a 11.1-mm screen, a 19.1-mm screen, or a 25.4-mm screen. Each screen-size treatment was ground at three separate time points (n = 3 replications/treatment). Grinding almond hulls and shells with no screen increased bulk density by 111% and minimized proportions of fine particles; therefore, almond hulls and shells ground using no screen were included as a treatment in the following experiments. In experiment 2, 364 steers (initial body weight [BW]: 257± 20.7 kg) were blocked by truckload (n = 4), stratified by BW, and assigned to pen within block. Pens were randomly assigned to 1 of 4 experimental diets (n = 10 pens/treatment). The control diet (CON) contained (DM basis) 39.5% dry-rolled corn, 7.5% supplement, 40% wet-corn gluten feed, and 13% prairie hay. Non-ground (13AH) or ground (13GAH) almond hulls and shells replaced prairie hay and were fed at 13% of diet DM or non-ground almond hulls and shells were fed at 26% of diet DM and replaced 13% prairie hay and 13% dry-rolled corn (26AH). Diets were limit-fed at 2.2% of BW daily (DM basis) for 56 d. Overall average daily gains (ADG) were greater (P  ≤ 0.05) for CON, 13AH, and 13GAH compared with 26AH. In addition, ADG from days 14 to 56 were greater (P = 0.03) for 13GAH and tended to be greater (P = 0.09) for 13AH compared with CON. Experiment 3 was a 4 × 4 replicated Latin square in which 8 ruminally cannulated heifers (initial BW = 378 ± 44.0 kg) were fed diets from experiment 2. Apparent dry matter digestibility did not differ (P = 0.21) among treatments. Total ruminal volatile fatty acid concentrations were greater (P  ≤ 0.03) for 13GAH and 13AH compared with 26AH and tended (P = 0.06) to be greater for 13GAH compared with CON. Overall, almond hulls and shells can be utilized as an alternative to prairie hay in limit-fed growing diets without negatively influencing rates of gain or diet digestibility. [ABSTRACT FROM AUTHOR]

Hyperlipidemia and oxidative stress are risk factors for atherosclerosis. In this study, we investigated the hypolipidemic and anti-lipoprotein oxidation activities of polyphenol-rich extracts from almond hulls using Triton WR-1339 and high-fat diet-induced hyperlipemic mice as experimental models. We demonstrated that the almond hull extract significantly reduced total cholesterol, triglycerides and low-density lipoprotein-related plasma cholesterol (LDL-C) in the two experimental models of hyperlipidemia, but significantly increased high-density lipoprotein-related plasma cholesterol (HDL-C). Another beneficial effect of the extract was its ability to reduce the atherogenic index and LDL-C/HDL-C ratio. However, the extract exhibited effective antiradical activity against 2,2-diphenyl-1-picrylhydrazyl and significantly protected lipoprotein-rich plasma from mice against oxidation induced by copper ion. The extract contains 342.63±3.44 mg/g total phenolics, 144.67±6.83 mg/g tannins, and 20.66±0.92 mg/g flavonoids. These finding indicate that almond hulls contain polar products able to lower plasma lipid concentrations and which might be beneficial for the treatment of hyperlipidemia and prevention of atherosclerosis.

Objective Oilseeds and nut co-products can be used as alternative feed ingredients in animal diets because they may have a lower cost than traditional ingredients. A study was, therefore, conducted to determine the chemical composition of copra, palm kernel, and nut co-products from South-East Asia or Australia. The hypothesis that country of production influences nutritional composition was tested. Methods Oilseed meals included 2 copra expellers, 3 copra meals, and 12 palm kernel expellers. One source of almond hulls and cashew nut meal were also used. Samples were obtained from suppliers located in South-East Asia or Australia. All samples were analyzed for dry matter, gross energy, nitrogen, amino acids (AA), acid-hydrolyzed ether extract (AEE), ash, minerals, insoluble dietary fiber, and soluble dietary fiber. Copra and nut co-products were also analyzed for total starch and sugars. Results Copra expellers had greater (p

Almond hulls (AH) are frequently used in dairy ruminant feeding, but information on variability of their nutritive value and their potential effects on CH4 production is still scarce. The influence of almond variety (Guara vs. Soleta) on chemical composition and energy value of AH was investigated using 10 samples per variety collected in 2 consecutive years. Guara-AH had greater (p ≤ 0.015) ash, protein, and fat content, but lower (p ≤ 0.001) fiber than Soleta-AH. The metabolizable energy content estimated from chemical composition and in vitro gas production was 8.5% greater for Guara than for Soleta samples. Harvesting year significantly affected most of the chemical fractions. The in vitro ruminal fermentation of diets for dairy ruminants including increasing amounts of dried AH (8, 16 and 24% of the total diet; fresh matter basis) indicated that AH can be included up to 16% of the diet, partially substituting corn, wheat bran and sugar beet pulp without detrimental effects on in vitro volatile fatty acid (VFA) production. In contrast, when AH replaced alfalfa hay and corn, VFA production was reduced at all levels of AH inclusion. No antimethanogenic effects of AH were detected in the in vitro incubations.

Objective: Oilseeds and nut co-products can be used as alternative feed ingredients in animal diets because they may have a lower cost than traditional ingredients. A study was, therefore, conducted to determine the chemical composition of copra, palm kernel, and nut coproducts from South-East Asia or Australia. The hypothesis that country of production influences nutritional composition was tested. Methods: Oilseed meals included 2 copra expellers, 3 copra meals, and 12 palm kernel expellers. One source of almond hulls and cashew nut meal were also used. Samples were obtained from suppliers located in South-East Asia or Australia. All samples were analyzed for dry matter, gross energy, nitrogen, amino acids (AA), acid-hydrolyzed ether extract (AEE), ash, minerals, insoluble dietary fiber, and soluble dietary fiber. Copra and nut coproducts were also analyzed for total starch and sugars. Results: Copra expellers had greater (p<0.05) concentrations of dry matter and AEE compared with copra meal. However, copra meal had greater (p<0.05) concentrations of total dietary fiber (soluble and insoluble) and copper than copra expellers. Palm kernel expellers from Indonesia had greater (p<0.05) concentration of histidine and tyrosine compared with palm kernel expellers from Vietnam. Almond hulls was high in dietary fiber, but also contained free glucose and fructose, whereas cashew nut meal was high in AEE, but low in all free sugars. Conclusion: Copra expellers have greater concentration of AEE, but less concentration of total dietary fiber when compared with copra meal, and except for a few AA, no differences in nutrient composition of palm kernel expellers produced in Indonesia or Vietnam were detected. According to the chemical composition of nut co-products, cashew nut meal may be more suitable for non-ruminant diets than almond hulls. [ABSTRACT FROM AUTHOR]

Almond processing generates a high quantity of by-products, presenting the untapped potential for alternative applications and improved sustainability in production. This study aimed to evaluate whether the incorporation of almond by-products (hulls/shells) can improve the biochemical characteristics of green bean pods when used as an alternative to traditional growing media in green bean plants. Four substrates were prepared: the Control substrate (C): 70% peat + 30% perlite; substrate (AS): 70% peat + 30% shells; substrate (AH): 70% peat + 30% perlite + 1 cm hulls as mulch; substrate (MIX): 70% peat + 15% shells + 15% hulls. Plants were grown in each of these substrates and subjected to two irrigation levels, 100% and 50% of their water-holding capacity. Biochemical parameters (photosynthetic pigments, total phenolics, flavonoids, ortho-diphenols, soluble proteins, antioxidant capacity) and color were evaluated in the harvested pods. Results showed that pods from plants growing in AH substrate presented statistically significant higher values in their total phenolic content, while AS and MIX substrates did not reveal significant benefits. Summarily, this study highlights the potential of almond hulls as a promising medium for green bean cultivation, particularly when employed as mulch. Further research is recommended to gain a more comprehensive understanding of the application of almond by-products as natural fertilizers/mulch.

BackgroundThe increasing production of almonds worldwide has resulted in the significant generation of byproduct streams that require end uses. One potential use for byproducts is for cultivation of additional food sources including insects. Studies were performed to determine if black soldier fly larvae (Hermetia illucens L.) could be cultivated on almond byproducts (hulls and shells) and to examine the effect of aeration and moisture on larvae growth and hull composition.ResultsIncreasing aeration from 0.04 to 0.36 mL min-1 g dry weight-1 tripled the harvest weight of larvae and increased larvae yield by a factor of five. Larvae calcium content increased by 18% with an increase in aeration from 0.04 to 0.95 mL min-1 g dry weight-1 . Moisture content also affected harvest dry weight and yield; increasing moisture content from 480 g kg-1 (wet basis) to 680 g kg-1 increased harvest weight by 56% and yield by a factor of 2. Variables did not affect larvae methionine and cysteine content. Low moisture content and aeration rate yielded an environment that supported microbial consumption of hulls over larvae consumption and growth.ConclusionsThe results demonstrate that almond hulls are a suitable feedstock for larvae production under controlled management of moisture content and aeration. © 2018 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Controlling postprandial hyperglycemia is considered as a viable prophylactic treatment for type 2 diabetes mellitus. A major strategy in decreasing postprandial glucose involves inhibition of the carbohydrate-hydrolyzing enzymes, α-amylase and α-glucosidase. The aim of this study was to evaluate the hypoglycemic potential of almond hull extract in vitro and in vivo. The in vitro results showed that, among the 0 %, 30 %, 50 % and 80 % ethanol extracts of almond hull, the 50 % ethanol extracts demonstrated the most significant inhibition of digestive enzymes. With in vivo tests, the blood glucose concentration in the control rats increased sharply near the peak glucose level in 15 min, while the peak glucose level of rats loading the almond hull extract occurred in 30 min. Therefore, almond hull extract can reduce postprandial blood glucose levels and delay the time to peak by about 15 min, providing a sustained and gradual release of energy. [Display omitted] • It's rich in nutrients, which has excellent water holding capacity. • It can effectively inhibit the activities of α-amylase and α-glucosidase in vitro. • It can lower and delay the peak of blood glucose, and sustainably release energy. • It provides a strong reference for the development of novel functional foods. [ABSTRACT FROM AUTHOR]

The effects of including almond hulls (AH) in the concentrate fed to light lambs on animal performance, diet utilization, and blood metabolites. Three isonitrogenous and isoenergetic concentrates were formulated with either 0 (control), 6 (AH6) or 12 (AH12) g of AH per 100 g (fresh matter basis). Thirty Manchega breed lambs (15 males and 15 females; 12.3 ± 0.18 kg body weight (BW)) were distributed into six homogeneous groups according to BW (3 groups of each sex), which were randomly assigned within sex to each experimental concentrate. Lambs were fed concentrate and barley straw ad libitum until reaching about 23.0 kg BW. There were no differences (P ≥ 0.182) between groups in final BW, intake of concentrate and straw, and feed conversion rate. Average daily gain and digestibility of dry matter and crude protein tended (P < 0.10) to decrease by the AH inclusion in the concentrate. Lambs fed AH12 showed greater (P < 0.05) urinary losses than those fed the control concentrate (15.4 and 11.5 g per 100 g of N intake, respectively), despite the similar N intake in all groups. Feeding AH did not affect (P ≥ 0.213) blood concentrations of albumin, globulins, urea, creatinine, glucose, total bilirubin and cholesterol or blood activities of hepatic enzymes. The post-mortem analysis revealed no differences among groups in pH and total volatile fatty acids (VFA) concentrations in the rumen of lambs, but NH 3 -N concentrations were lower (P < 0.05) in the lambs fed the concentrates with AH. In addition, lambs fed AH12 diet had lower (P < 0.05) molar proportions of propionate and greater (P < 0.05) proportions of butyrate compared with lambs fed control and AH6 concentrate. In general, no concentrate x sex interactions were observed, and sex had no effect on the measured parameters except for some differences in ruminal VFA profile. In conclusion, AH can be included at in light lambs' concentrate up to 12 g per 100 g of concentrate without impairing animal growth. • Almond hulls (AH) were evaluated as feed ingredient in concentrates for light lambs 2. • Using up to 120 g/kg of AH did not affect lamb growth, diet digestibility and plasma 3 parameters 4. • Inclusion of 120 g/kg of AH increased N excretion 5. • AH can be used as feed ingredient in light lambs feeding 6. • Optimal level of AH in lambs' diets would depend on nutritional quality of AH 7. [ABSTRACT FROM AUTHOR]

This study explores the co-hydrothermal treatment (co-HTT) of almond hulls and Chlorella Vulgaris using seawater as an alternative HTT medium. The influence of the feedstock (individual biomass and all the possible binary mixtures) was systematically evaluated under different conditions (reaction temperatures and times). The feedstock mixture and hydrothermal conditions significantly influenced the overall product distribution: gas (1–5%), hydrochar (6–56%), biocrude (6–55%), and aqueous fraction (33–52%), along with the most representative physicochemical and fuel properties of these products. Notably, the biocrude had a calorific value of 24–31 MJ/kg, whereas the hydrochar shifted between 3 and 26 MJ/kg. The degradation of abundant polysaccharides in almond hulls produced acidic species, promoting the degradation of proteins to N-containing species in biocrude. The synergies between microalgae and almond hulls favored the deamination of amino acid and repolymerization of formed monomers. Process optimization revealed that the best biocrude production (59% yield and HHV = 28 MJ/kg) was obtained by treating C. Vulgaris at 268 °C for 180 min. Contrarily, the HTT of almond hulls under optimum processing conditions (300 °C and 112 min) also produced an energy-dense biocrude (29 MJ/kg) but with a much lesser yield (16%). However, such a low biocrude production can be synergistically increased up to 33 %, maintaining the HHV (31 MJ/kg), including up to 61 wt% of C.Vulgaris into the feedstock, with a feedstock energy recovery of 75%. Holistically, the co-HTT of 40 wt% C. Vulgaris and 60 wt% almond hulls at 300 °C for 180 min produced energy-dense liquid (23% yield and HHV = 32 MJ/kg) and solid (29% yield and HHV = 25 MJ/kg) biofuels simultaneously, with a feedstock energy recovery of 80%. Given these excellent prospects, this strategy provides timely and new insights into developing synergetic strategies to utilize microalgal and lignocellulosic biomasses more efficiently, paving the way toward developing holistic and unseasonal biorefinery processes. [Display omitted] • A novel 'sea-thermal' synergistic strategy for lignocellulosic and algal biomasses. • Full analysis of bilateral lignocellulose-algae synergistic/antagonistic interactions. • Improved products were obtained from binary feedstocks compared to individual ones. • Feedstock mixtures exerted different impacts depending on the time and temperature. • Detailed conditions for liquid/solid biofuels from individual/binary feedstocks. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the in vitro digestibility and in sacco disappearance of dry matter (DM) and neutral detergent fibre (NDF) in total almond hulls (TAH), pure almond hulls (PAH) or Debris. The TAH were used because there are no data on the effect of debris (non-hull material) on the nutritional value of almond hulls. Twelve samples of commercial almond hulls were used, with one subsample representing the TAH and the other subsample hand sorted to separate the hulls (PAH) from Debris. Gas production and Ankom Daisy method were used to determine in vitro digestibility, while two rumen-fistulated cows were used to measure in sacco disappearance of PAH and TAH. For in vitro digestibility, both PAH and TAH were more digestible and had greater gas production than Debris. The PAH had greater in vitro true digestibility on a DM basis and NDF digestibility at 48 and 72 h compared with TAH. Nonpareil hulls provided greater metabolizable energy (ME) concentration when compared with other almond varieties, with PAH supplying numerically more ME than TAH for both varieties. For in sacco disappearance, PAH had greater DM and NDF disappearance along with a greater rate of disappearance for NDF compared with TAH. This research demonstrated that Debris is highly indigestible; therefore, hulling, agronomic and harvesting practices should be focused on reducing Debris in commercial almond hulls to improve their nutritive value as a feedstuff for livestock. [ABSTRACT FROM AUTHOR]

California is the leading state for the production of almonds, with more than 400,000 bearing hectares of orchards that produced approximately 1 billion kilograms of shelled nuts in 2017. Almond hulls (AH) are a regional by-product feedstuff fed predominantly to dairy cattle in California. A 2012 study surveyed 40 dairy farms in California and found that 39 out of 104 total mixed rations contained AH, with a mean daily feeding rate of 1.45 kg/cow. In 2017, approximately 2 billion kilograms of AH was produced. At a feeding rate of 1.45 kg/cow daily, even if all 1.7 million lactating cows in California are consuming AH, there will be a surplus of AH on the market as the approximately 130,000 nonbearing hectares come into nut production. Therefore, the potential of feeding varying amounts of AH to lactating dairy cows was investigated using 12 Holstein cows with 4 primiparous and 8 multiparous cows. The dietary treatments were 4 total mixed rations containing 0, 7, 13, or 20% AH. The AH used contained 12.8% crude fiber (as-is basis), which was below the 15% legal limit set by state feed regulations. Diets were formulated so that as the inclusion rate of AH increased, the amount of steam-flaked corn and soyhull pellets decreased and soybean meal inclusion increased. Experimental design was a replicated 4 × 4 Latin square. Diet had a cubic effect on actual milk yield, energy-corrected milk yield, and dry matter intake, with the 7% AH diet having the highest values and the 13% AH diet having the lowest. The percent and yield of total solids and the yields of lactose and fat did not differ with diet, but percent and yield of protein declined linearly with increased AH inclusion, and fat percent increased linearly. Apparent total-tract digestibilities of dry matter and organic matter were higher with the inclusion of AH in the diet. Total percentage of the day spent ruminating increased linearly with higher amounts of AH. Overall, this work demonstrated that AH can be fed at varying amounts, up to 20% of the diet, to lactating dairy cows to support high levels of milk production and that increasing amounts of AH (up to 20%) in the diet could lead to improved digestibility and milk fat percentage but decreased milk protein production. [ABSTRACT FROM AUTHOR]

The search for waste minimization and the valorization of by-products are key practices for good management and improved sustainability in the food industry. The production of almonds generates a large amount of waste, most of which is not used. Until now, almonds have been used for their high nutritional value as food, especially almond meat. The other remaining parts (skin, shell, hulls, etc.) are still little explored, even though they have been used as fuel by burning or as livestock feed. However, interest in these by-products has been increasing as they possess beneficial properties (caused mainly by polyphenols and unsaturated fatty acids) and can be used as new ingredients for the food, cosmetic, and pharmaceutical industries. Therefore, it is important to explore almond’s valorization of by-products for the development of new added-value products that would contribute to the reduction of environmental impact and an improvement in the sustainability and competitiveness of the almond industry.

The search for waste minimization and the valorization of by-products are key to good management and improved sustainability in the food industry. The great production of almonds, based on their high nutritional value as food, especially almond kernels, generates tons of waste yearly. The remaining parts (skin, shell, hulls, etc.) are still little explored, even though they have been used as fuel by burning or as livestock feed. The interest in these by-products has been increasing, as they possess beneficial properties, caused by the presence of different bioactive compounds, and can be used as promising sources of new ingredients for the food, cosmetic and pharmaceutical industry. Additionally, the use of almond by-products is being increasingly applied for the fortification of already-existing food products, but there are some limitations, including the presence of allergens and mycotoxins that harden their applicability. This review focuses on the extraction technologies applied to the valorization of almond by-products for the development of new value-added products that would contribute to the reduction of environmental impact and an improvement in the sustainability and competitiveness of the almond industry.

Effects of ensiled greenhouse wastes (GHW), alkali-treated GHW and almond hulls (AH) on growth performance were studied on 24 Assaf lambs. All lambs were males with an average weight of 36.2 kg (S.D. = 2.1 kg) at the beginning of the experiment. Animals were randomly divided into 4 groups of 6 lambs each. Lambs in each group received individually corn-soybean meal (SBM) total mixed rations (TMR). Rations were incorporated with a fixed amount (200 g/kg) of the treated raw ingredients: ensiled greenhouse wastes, alkali-treated GHW and ensiled AH. All rations were isonitrogenous and isocaloric. The growth experiment lasted 80 d. Both chemical and biological treatments had significant effects on improving crude protein (CP) and fiber fractions. At termination of the experiment, lambs fed treated ingredients (i.e., ensiled GHW, alkali-treated GHW, ensiled AH) had better (P < 0.05) feed conversion ratios and consumed less (P < 0.05) feed. Treated GHW and AH had no effect on average daily gain (P = 0.14) and total gain (P = 0.21). Cost of gain was significantly lower in lambs fed the treated ingredients. [ABSTRACT FROM AUTHOR]

The acid-free hydrothermal microwave–assisted selective scissoring (Hymass concept) of cellulosic substrates is gaining keen interest in the field of materials science. Besides, implementing catalytic methodologies to upgrade side streams produced during this process could contribute to better, holistic utilisation of the starting feedstock. This work depicts a zero-waste biorefinery concept based on cellulose defibrillation from almond hulls using various hydrotreatment technologies (hydrogenation and hydrodeoxygenation) for downstream processing on a ruthenium catalyst. Therein, the hemicellulose separated from the biomass preconditioning step was converted into sugar alcohols and/or marketable polyols with a relatively high yield (47.4%) by hydrolytic hydrogenation (437 K, 3h, 5.0 MPa H 2). Meanwhile, a family of bioactive compounds (3-hydroxypyridines) could be directly extracted from the hydrolysate stream derived from microwave digestion, along with an energy carrier that was chemically stabilised (503 K, 60 min, 4.0 MPa H 2) to obtain fuel additives (diethyl succinic acid, DES) and/or fuel intermediates. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the effect of dietary replacement of alfalfa with urea-treated almond hulls (UAH) on DM and nutrients intakes, growth performance, diet digestibility, microbial N supply (MNS), N retention, rumen fermentation parameters, and blood metabolites in fattening male Shall lambs (29.9 ± 1.9 kg initial BW). Three diets, with equal ME and CP concentrations and a forageto- concentrate ratio of 40 to 60, were formulated in which alfalfa was replaced by different levels (0, 200, or 400 g/kg of diet DM) of UAH. Experimental diets were randomly assigned to the 3 groups (n = 8/group) in a completely randomized design for a 74-d period (14 d for adaptation and 60 d for data collection). Diets were offered as a total mixed ration to ensure 10% orts. Dry matter and nutrients intakes, animal growth, diet digestibility, MNS, N retention, rumen fermentation parameters, and plasma metabolites were determined. The dietary substitution of UAH for alfalfa had no effects on DMI (linear, P = 0.96; quadratic, P = 0.86), ADG (linear, P = 0.35; quadratic, P = 0.19), and G:F (linear, P = 0.66; quadratic, P = 0.13). In vivo digestibility coefficients of DM (linear, P = 0.82; quadratic, P = 0.42), OM (linear, P = 0.73; quadratic, P = 0.95), CP (linear, P = 0.24; quadratic, P = 0.66), and ash-free NDF (linear, P = 0.69; quadratic, P = 0.74) were not affected by the dietary treatment. Feeding lambs on diets containing UAH instead of alfalfa had no effects on MNS (linear, P = 0.63; quadratic, P = 0.68) and N retention (linear, P = 0.44; quadratic, P = 0.17). Rumen pH (linear, P = 0.26; quadratic, P = 0.071), ammonia N (linear, P = 0.39; quadratic, P = 0.13), and VFA (linear, P = 0.091; quadratic, P = 0.86) concentrations, acetic acid-to-propionic acid ratio (linear, P = 0.93; quadratic, P = 0.62), and protozoa population (linear, P = 0.62; quadratic, P = 0.22) were not influenced by the experimental diets. Substituting alfalfa with UAH had no effects on the plasma concentrations of glucose (linear, P = 0.55; quadratic, P = 0.91), triglycerides (linear, P = 0.97; quadratic, P = 0.44), cholesterol (linear, P = 0.71; quadratic, P = 0.70), urea N (linear, P = 0.084; quadratic, P = 0.12), total protein (linear, P = 0.53; quadratic, P = 0.96), albumin (linear, P = 0.43; quadratic, P = 0.39), and globulin (linear, P = 0.39; quadratic, P = 0.25). It is concluded that UAH can be fed to fattening Shall lambs as a total replacement (400 g/kg of diet DM) for alfalfa without negative effects on animal performance. This byproduct can be a safe feedstuff to use in sheep diets and could help to reduce environmental pollution. [ABSTRACT FROM AUTHOR]

The nutritive values of almond hulls (AHs), alfalfa (ALF), and sugar beet pulp (SBP) were determined using the in situ nylon bag technique. The ruminal dry matter (DM) degradation kinetics of 4 varieties of AHs were compared with ALF and SBP. The almond varieties tested were Rabbi (RAB), Mamaii (MAM), Shahrud 15 (SH15), and Shokufe (SH). Samples were incubated in triplicate at 0, 4, 8, 12, 16, 24, 48, 72, and 96 h in 3 rumen-fistulated steers. The average total degradability fraction (TDF) of DM in AHs was 89.00%. Although the TDF of AHs (86.50%) was lower than that of SBP (98.00%), it was higher (P < 0.05) than that of ALF (67.00%). The soluble (a) fraction in AHs (55.00%) was higher than in both ALF (20.00%) and SBP (26.00%). This high (a) fraction of AHs was attributed to their relatively higher nonfibrous carbohydrate and lower neutral detergent fiber content than ALF and SBP. The degradation rate of ALF (0.14%) was significantly higher (P < 0.05) compared to the other samples, whereas that of SBP (0.05%) was not significantly different (P > 0.05) from those in AHs. The results showed that AHs are potential feed materials for ruminants. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel strategy to reduce feedstock-dependence: biomass and plastic covalorisation. • Full assessment of bilateral biomass-plastic synergistic/antagonistic interactions. • Seawater promoted and inhibited the extension of several hydrothermal transformations. • Water salinity (deionised water/seawater ratio) influenced the process. • Detailed conditions for liquid/solid biofuels from individual/binary feedstocks. This work first-time addresses the synergetic hydrothermal co-valorisation of almond hulls (an unavoidable food waste) and FFP2 face masks (a common plastic material) using seawater (a sustainable reaction medium). The effects of the feedstock composition (each material alone and all possible binary combinations) and the reaction medium (deionised water, seawater and all possible binary mixtures) have been evaluated at 350 °C and 170 bar over a wide range of reaction times (20–180 min). Bilateral biomass-plastic synergistic and antagonistic interactions between both feedstocks, combined with several promoting and inhibiting effects displayed by seawater, ruled the distribution of the reaction products and their most important physicochemical and fuel properties. Process optimisation revealed that the formation of an energy-dense (32 MJ/kg) liquid biofuel was maximised (26% biocrude yield) by conducting the process with almond hulls in deionised water for 115 min. At the same time, face masks promoted solid biofuel formation (83% hydrochar yield, 46 MJ/kg) by coprocessing an almond hulls/disposable face masks mixture (8:92 wt%) in salted (seawater/deionised water mixture with 37471 ppm salinity) water for 180 min. Conducting the process with seawater (44608 ppm salinity) for 180 min allowed coprocessing of both materials (22/78 wt% almond hulls/face masks) efficiently to maximise biofuels production (13% biocrude yield, HHV = 33 MJ/kg and 67% hydrochar yield, HHV = 49 MJ/kg). These results are a breakthrough in developing season-free and flexible biorefineries, which contribute to reducing pollution and bringing out the hidden value of human activity common residues. [ABSTRACT FROM AUTHOR]

Over 58% of the dry matter content of the hulls from the commercial almond ( Prunus dulcis (Miller) D.A. Webb) is soluble in warm water (50–70 °C) extraction. The water-soluble extractables include useful amounts of fermentable sugars (glucose, fructose, sucrose), sugar alcohols (inositol and sorbitol), polysaccharides, and other components. Extraction rate data were taken over a range of temperatures and particle sizes (including whole hulls). Equilibrium concentrations and liquid retention data were taken over a wide solubles concentration range, enabling use of a standard leaching model for the calculation of stage-to-stage concentrations and flows in an ideal countercurrent extractor. The relations between recovery, product concentration, number of ideal stages, and ratio of solvent-to-feed were determined using the model. The data indicate that a solutes concentration of 18–20% dry matter in the concentrate liquid is attainable. Due to the nature of the native hulls to preferentially absorb water from dilute solutions, initial contact of hulls with the overhead liquid concentrate (if well below ∼18% solutes) may result in a significant enhancement of overhead concentration. [ABSTRACT FROM AUTHOR]

Highlights: [•] High levels of fermentable sugars (25–33% d.b.), and sugar alcohols present in almond hulls. [•] Potential feedstock for biofuels production, and/or inositol and sorbitol recovery. [•] Theoretical ethanol yields of 130–176L/tonne. [ABSTRACT FROM AUTHOR]

The search for waste minimization and the valorization of by-products are key to good management and improved sustainability in the food industry. The great production of almonds, based on their high nutritional value as food, especially almond kernels, generates tons of waste yearly. The remaining parts (skin, shell, hulls, etc.) are still little explored, even though they have been used as fuel by burning or as livestock feed. The interest in these by-products has been increasing, as they possess beneficial properties, caused by the presence of different bioactive compounds, and can be used as promising sources of new ingredients for the food, cosmetic and pharmaceutical industry. Additionally, the use of almond by-products is being increasingly applied for the fortification of already-existing food products, but there are some limitations, including the presence of allergens and mycotoxins that harden their applicability. This review focuses on the extraction technologies applied to the valorization of almond by-products for the development of new value-added products that would contribute to the reduction of environmental impact and an improvement in the sustainability and competitiveness of the almond industry. [ABSTRACT FROM AUTHOR]

The search for waste minimization and the valorization of by-products are key practices for good management and improved sustainability in the food industry. The production of almonds generates a large amount of waste, most of which is not used. Until now, almonds have been used for their high nutritional value as food, especially almond meat. The other remaining parts (skin, shell, hulls, etc.) are still little explored, even though they have been used as fuel by burning or as livestock feed. However, interest in these by-products has been increasing as they possess beneficial properties (caused mainly by polyphenols and unsaturated fatty acids) and can be used as new ingredients for the food, cosmetic, and pharmaceutical industries. Therefore, it is important to explore almond's valorization of by-products for the development of new added-value products that would contribute to the reduction of environmental impact and an improvement in the sustainability and competitiveness of the almond industry. [ABSTRACT FROM AUTHOR]

For the first time, this work investigates the achievability of developing a biorefinery concept around almond hulls by hydrothermal treatment (HTT), thoroughly scrutinising the influence of the temperature (200–300 °C), pressure (100–180 bar), time (20–180 min) and solid loading (5–25 wt%). This process allowed the conversion of almond hulls into four main products: gas (2–13%), bio-oil (2–12%), aqueous (4–69%) and hydro-char (17–89%). The gas consisted of a mix of H 2 , CO 2 , CO and CH 4 with a LHV fluctuating from 1 to 13 MJ/m3 STP. The bio-oil comprised a mixture of alkanes, aldehydes, ketones, phenols, furans, benzenes and nitrogen compounds with a HHV between 21 and 31 MJ/kg. The solid product resembled an energetic hydro-char material (HHV 21–31 MJ/kg), while the aqueous effluent comprised a mixture of value-added chemicals, including saccharides and small oxygenated compounds. The production of biofuels can be maximised at 256 °C and 100 bar, using a 5 wt% solid loading for 157 min, conditions at which 43% of the original feedstock can be converted into an elevated energy-filled bio-oil (11% yield, 30 MJ/kg), along with a high energetic hydro-char (32% yield, 29 MJ/kg). Regarding value-added chemicals, up to 10% of the almond hulls can be converted into a bio-oil with a high proportion (45%) of phenolic species at 250 °C and 144 bar with a solid loading of 5 wt% for 167 min. In comparison, a sugar-rich (81 C-wt%) solution can be produced in high yield (54%), by treating a 24 wt% suspension at 252 °C and 180 bar for 153 min. Therefore, the versatility, novelty and intrinsic green and holistic nature of this 'almond-refinery' concept exemplify a landmark achievement in future energy and chemicals production from biomass, which might help render the complete bio-refinery for almond hulls more cost-effectively and ecologically feasible. Unlabelled Image • Environmentally friendly biorefinery concept developed around almond hulls • Production of high-energy biofuels (bio-oil and hydro-char) and sugar-rich solutions • Detailed effect of process conditions: temperature, pressure, time and solid loading • Optimum conditions for bio-fuels production: 256 °C, 100 bar, 5 wt% solid, 157 min • Optimum conditions for sugars production: 252 °C, 180 bar, 24 wt% solid, 153 min [ABSTRACT FROM AUTHOR]